CONTAINER FILLED BY THE METHOD; A PACKAGE TO BE FILLED BY THE

METHOD; AND AN APPARATUS TO PERFORM THE METHOD

Field of the Invention

This invention relates to a method of aseptic filling flexible bag containers; a container filled by the method; a package to be filled by the method; and an apparatus to perform the method; the method being to fill flexible bag type containers for liquids or flowable suspensions of paniculate in liquids, which containers incorporate a collar-shaped opening. Background Art

The closest prior art relevant to this invention is generally described in US patent 4,805,378 (Anderson).

Anderson teaches a method including a step of sterilising sealed empty flexible bag containers, incorporating a collar-shaped opening having a heat sealable flap on one side and, on the other, a rupturable closure.

The entire disclosure of US 4,805,378 is imported into this specification by reference. Reference is made also to US patents 4,542,530 (Thomas et al) and 4,672,688 (Kalkipsakis) which relate to flexible containers having collar-like openings.

Thomas discloses that the container can be sealed at manufacture by a flap temporarily sealed to the surrounding edges of the collar inwardly of the wall, preferably to a flange. The container is filled with liquid by forcing that liquid into the collar at a pressure high enough to break the temporary seal. The flap in that case is attached to the flange (forming an extension of the collar inside the bag) by permanent joints partly surrounding the temporary seal. After filling, the flap is permanently fully joined to the flange by heat fusion. The flap may be punctured when withdrawal of the liquid is required.

Kalkipsakis in the US patent 4,672,688 taught an improvement to Thomas et al in which a flap of the same general type could be partially joined to form a divergent entry chute to obtain an increased rate of filling, and improvement for suspensions containing solids such as pineapple crush. In the method of US 4,805,378 (Anderson) a container is filled via an upstanding plastics collar, at one end of which a first flange is heat fused to the flexible plastics sheet wall of the container surrounding a filling opening in the container and, at a second flange at the opposite end of the collar, a rupturable sheet plastics membrane is also heat fused. The sheet plastics membrane, which is heat sterilised in manufacture but which most likely would be re-contaminated externally before filling, is re-sterilised immediately prior to filling by a fluid (e.g. pressurised steam) after being brought into engagement with a filling head of an

aseptic filler. In the described method, an incision tool forming part of the filling head, sterilised along with the exterior of the membrane, is advanced to cut the membrane then withdrawn to enable admission of the liquid to be packaged through the bore of the collar and through gaps formed between the flap partially heat fused to the flange inside the container.

As disclosed in the Anderson patent, the cutting of the re-sterilised membrane involves making a pair of straight incisions, crossed at right angles, passing through the centre of the membrane and extending radially outwardly to a point just inside the outer flange of the upstanding plastics collar. As the liquid or liquid-like product flows into the bag to fill it, the four cut tips or "reversed petals" of the membrane turn inwardly with the flow and extend towards the inner end of the collar where it is connected to the bag in the region that is subsequently sealed closed as described.

There are occasionally experienced instances of unreliability with the Anderson arrangement in that the four petals of the top membrane, since they remain on the filled sealed package, are difficult to clean underneath to remove remnants of the packaged product inside of the collar during the flushing cycle. Also, the petals tend to slightly reduce the flow rate of product into the container during filling which can be detrimental to production rates particularly with high viscosity liquids or paniculate containing products. Furthermore, there is a risk that the tips of the petals might wrap underneath the inside corner of the flange and be caught in the subsequent final heat sealing operation. If this happened there would be a potential leakage path bypassing the seal; or a potential source of failure of the seal. Accordingly, the axial height of the collar should be sufficient in relation to the diameter of the opening to reduce the likelihood of this possibility. In use, the diameter of the opening as disclosed in the Anderson patent is known to be in the range of 16 to 32mm. With a desired future extension of the size of the opening up to about 60 to 70mm, using the arrangement disclosed in the patent would require a corresponding increase in the axial height of the collar. The only need for the increase in the height of the collar is to ensure the cut petals of the membrane do not enter the sealing region. Such a high collar profile would be unacceptable to fillers, and end-users, of the package. Objects of the Invention

It is therefore an object of this invention to provide a method, a package, an apparatus, and a filled package, which will address at least one of the disadvantages of the prior art.

Summary of the Invention

The invention provides a method of aseptically filling a flexible bag-type container through a container inlet , said container having its internal portions sterilised before being filled; said container including a flap to form a seal with the container inlet to thereby form a sealed container inlet and further including at least two additional attachments to attach said

flap to said container or a region around said container inlet; said method comprising the steps of:

(a) placing said sealed container inlet in a desired position relative to a filling dispenser;

(b) exposing said sealed container inlet to a sterilising fluid for a predetermined sterilising time;

(c) withdrawing said sterilising fluid after said predetermined sterilising time has elapsed;

(d) unsealing said flap from said container inlet without puncturing, damaging, cutting or otherwise compromising the integrity of said flap;

(e) introducing a product from the filling dispenser through the container inlet to fill the container;

(f) closing said container inlet by forming a seal between the flap and the container inlet, to form a re-sealed container inlet;

(g) removing said container.

Preferably step (f) of said method is achieved by a re-forming of the seal that existed before step (d) was performed.

Preferably step (f) of the method is achieved by the forming of a stronger seal than that which existed before step (d) was performed.

Preferably, step (a) of said method is achieved by first positioning said container on a container support.

After said container is positioned on said container support, it is preferable that relative movement between said container support and said filling dispenser positions said container relative to said filling dispenser so as to receive sterilising fluid at step (b) and product at step (a).

Preferably said relative movement is achieved by said container support moving towards the filling dispenser, which remains stationary.

Preferably between steps (e) and (f) an additional step is added of flushing remnants of said product from the flap and said container inlet.

Preferably between steps (f) and (g) an additional step is added in which said re-sealed

container inlet is exposed to a sterilising fluid for a predetermined sterilising time; the sterilising fluid being removed after a predetermined sterilising time has elapsed.

Preferably said step which is added step between step (f) and step (g) includes the introducing of sterilising fluid into the space between said filling dispenser and said re-sealed container inlet; removing the sterilising fluid through the filling dispenser to also sterilise said filling dispenser and to flush any product remaining around the outside of said resealed container inlet.

Preferably after step (i) a step is added which includes the introducing of sterilising fluid into the space between said filling dispenser and said re-sealed container inlet; and withdrawing the sterilising fluid through the filling dispenser in order to also sterilise said filling dispenser and to flush away product remaining around the outside of said resealed container inlet.

Preferably step (d) is performed by said filling dispenser which includes a member having a blunt end which moves relative to said filling dispenser to push said flap away from said container inlet thereby breaking said seal, without puncturing said flap.

Preferably said blunt member also serves to prevent said product from exiting said filling dispenser, as it is pushing said flap away from said container inlet.

Preferably step (d) is performed by the pressure effect exerted by steam of sterilising fluid acting on the surface of said flap.

Preferably step (d) is also performed by the temperature of the steam or sterilising fluid.

Preferably step (f) is performed by means of a welding process.

Preferably heat and the necessary compressive force to achieve said welding process is applied from a position opposite said filling dispenser.

Preferably said flap has two surfaces and can only be welded to one surface of said container.

The invention also provides a container filled by the method of any one of the above paragraphs.

The invention further provides an apparatus for the filling of a container by the method of any one of the above paragraphs.

The invention also provides apparatus for the filling of a container, said container of the bag type and having an inlet sealed by a flap and the insides of said container being sterile; said apparatus including a filling dispenser having a nozzle, said nozzle being adapted to pass

product into said container, and being adapted to be sealed by a member having a blunt end, said member and its blunt end preventing product passing into said inlet, until such time as said seal between said flap and said inlet has been broken by force applied from said blunt end against said flap without damaging or compromising the integrity of said flap.

Preferably said member also includes a fluid passage therethrough to enable sterilising fluid to pass there along to said inlet and said flap to sterilise same.

The invention also further provides an aseptic container including a bag type body and an inlet portion, said inlet portion being preformed and being welded to said bag to form an inlet, said container having a flap which is sealed to said inlet, said flap in addition to being attached to said inlet to form a seal, having at least one additional attachment so that when said seal is broken said flap remains in a position which allows the flap to be re-sealed to said inlet.

Preferably said at least one additional attachment of said flap is between said flap and said body.

Preferably said at least one additional attachment of said flap is between said flap and said inlet portion.

Preferably said flap has two surfaces, one surface being adapted to enable said flap to be welded to said inlet portion or said body, whereas its second surface is of a material which cannot be welded to said body of said container. The invention further provides a method of aseptically filling a container in the form of a flexible bag through a container inlet from a filling dispenser, including the steps of:

(a) providing a sterilised sealed empty container in which the container inlet has a temporarily sealed flap immediately surrounding said inlet and at least two additional attachments of said flap partially surrounding said temporary seal; (b) sterilising and maintaining the internal surfaces of the filling dispenser in a sterile state;

(c) bringing the inlet of the container into abutment with a nozzle of the filling dispenser by means of a moveable container support;

(d) introducing sterilising fluid into the space between said nozzle and said temporarily sealed inlet from said nozzle and removing the sterilising fluid through the nozzle following a sterilising time period;

(e) unsealing said temporary seal without puncturing said flap;

(f) introducing a product from the nozzle through the inlet to fill the container;

(g) optionally flushing remnants of said sterilised product from the flap and interior side of the inlet, using sterilising fluid;

(h) closing the inlet by sealing the flap to the inlet;

(i) removing said container from said dispenser. Brief Description of the Drawings

A embodiment of the invention, will now be described, by way of example only with reference to the accompanying drawings in which ;

Figure 1 is a schematic cross-sectional view of part of the container and collar; and

Figure 2 is a schematic cross-sectional view of the filling dispenser, a container and container sealing apparatus, as positioned during the filling cycle.

Detailed Description of the Drawings

Figure 1 illustrates a bag 10 which includes a flexible container wall 12 heat sealed, at the periphery 14, to the lower wall 16. A flap 18 extends across an opening 20 in the flexible container wall 12 into which fits a collar 22. A flange 24 of the collar 22 is fused by a temporary seal 26 to the periphery of the opening 20 and the flap 18 is partly fused at points or lines 28 to the flange 24 of the collar 22 radially outwardly of the temporary seal 26. Alternatively, the flap 18 may be partly fused to the inside of the flexible container wall 12 surrounding the flange 24. The collar 22 is secured to the flexible container wall 22 and the flap 18 to the flange 24 or flexible container wall 12 by conventional heat sealing machinery.

The surface of the flap 18 which faces the lower wall 16 is not heat-sealable therewith, but the surface of the flap 18 which faces the flange 24 is heat sealable with flange 24. The above mentioned temporary seal 26 is effected with close control of the fusion process to be sufficiently strong to withstand, without release, the sterilisation step which generally involves the introduction of pressurised steam into the collar 22. Other sterilising fluids can be used. If steam is used as the sterilising fluid and the intended filling contents are categorised as a high acid food then a sterilising temperature of 110°C for 5 seconds is typical. If the product to be filled is categorised as a low acid food then the sterilising step involving steam might involve a temperature of 140°C to 150°C for up to 3 seconds. The flap 18 can be a laminate of a polyester facing lower wall 16 and a polyethylene facing flexible container wall 12. In instances when the lower wall 16 and the flexible container wall 12 are of polyethylene or polypropylene, the temporary seal 26 and join with the collar 22 are formulated to withstand sterilising temperatures and the attendant pressure without detaching the flap 18 or compromising the flap 18. By compromising it is meant anything that results in the inability of the flap to perform its task for the designed period of time and expected conditions. Thus compromising could include tearing, rupturing, weakening,

reduction in durability, or failure during transport resulting from the opening process. In some situations the temporary seal 26 can be supported from the back face during the sterilising step by a heat sealing anvil 60 supporting the heat sealing member 56 described below. The filling apparatus 29 as shown in Figure 2 includes a filling head 30 having a body section 32 which includes a product inlet channel 34 closed by a valve member 36. Valve member 36 is reciprocally mounted within the body section 32. The valve member 36 includes a valve head 38 which seals an outlet 40 when in contact with an O-ring seal 42.

A blunt member or end 44 is attached to the lower portion of the valve head 38 in order to part the temporary seal 26 between the flap 18 and the flange 24, without puncturing or tearing or otherwise compromising the integrity of the flap. The other points of attachment 28 keep the flap 18 in position, but as the seal 26 with collar 22 has been broken a fluid passage to the internal portions of the container 10 exists and through which the container 10 can be filled. In Figure 2, the blunt end is formed integrally with the valve head 38, however, if desired, the blunt end could be an instrument formed separately and attached to the end of the valve head 38.

Alternatively to the blunt end 44, the temporary seal 26 can be unsealed or detached, immediately after the sterilisation step by a short period of pressurisation, by steam or other fluid sterilant, at a pressure and temperature greater than that required for sterilising but not so high as to tear, melt or otherwise puncture or compromise the integrity of the flap.

The sterilising fluid inlet 46 and outlet 48 can in one embodiment be connected to the valve outlet 40 below the seal 42. The number of inlets 46 and outlets 48 can be varied. By positioning several inlets 46 around the periphery of the outlet 40 an efficient cleaning action can be achieved. One large exhaust port or outlet 48 is usually sufficient. The final sealing step of the complete filled container is generally as described in US patent 4,805,378.

In another embodiment an alternative form of sterilising fluid inlet may be incorporated, in addition to or instead of, the inlet 46. A fluid passage 54 is provided passing lengthways through the valve member 36 and the blunt end 44. The embodiment of figures 1 and 2 operates as follows. A flexible container 10 is taken by clamps 50 and lifted into alignment with the filling head 30 such that the upper flange of the collar 22 tightly abuts against a seal 52 on the body section 32. After contact is made between the body section 32 and the collar 22, a sterilising fluid (either gas or liquid such as steam) is passed into the outlet 40 via the inlet 46 and/or fluid passage 54 and sterilises the inner surfaces of the outlet 40 of the valve head 38, the blunt end 44 and the internal surface of the collar 22. Subsequently the sterilising fluid is withdrawn through the outlet 48.

After completion of the sterilisation step the blunt end 44 is advanced into the opening to

part the temporary seal 26. The sealing of the flap 18 is so configured that upon breaking or parting of the temporary seal 26, the flap 18 is non-occlusive of the opening through collar 22 but remains positioned relative to the opening of collar 22 to be subsequently re-sealable back over the opening of collar 22 to provide a permanent seal for the filled container 10. A flap 18 of the form shown in US patent 4,672,688 (Kalkipsakis) is particularly adaptable for this purpose for viscous or coarse paniculate fillings. Upon the completion of filling, the valve member 36 closes the inlet 34 at the O-ring seal 42. A trapdoor 58 is then withdrawn and the heat sealing member 56 is brought into contact with the flexible container and when raised to an appropriate temperature results in the welding of the flap 18 to the flange 24 of the collar 22 (or, if preferred, to the inside surface of the flexible container wall 12) to seal the flexible container 10.

After sealing, sterilising fluid is introduced again through the inlet into the collar 22 to flush all product from the collar 22 and exterior of the newly reformed seal and from the filling head 30 and the blunt end 44. In some situations it is preferable to commence this flushing step immediately prior to the heat sealing step in order to flush fibrous or paniculate type foodstuffs from around those areas of the flap 18 and flange 24 that will be fused to each other in the heat sealing step. The flushing cycle may be continued during the commencement of the heat sealing step to ensure no re-contamination of the area to be heat sealed while the heat sealing anvil 60 and heat sealing member 56 squash the container immediately prior to heat sealing.

On completion of the sealing step the filled flexible container is withdrawn from the filling head 30.

The movements and controls of the filling machine and the filling head 30 are essentially the same as that described in US 4,805,378. If required, the container 10 can remain stationary while the filling head 30 moves towards the container 10.

This invention provides an improved means of ensuring aseptic filling of flowable products as well as an improved possibility of achieving reliable sealing of the bag. This happens despite the fibrous or paniculate nature of any particular product put into the bag.

The invention can also allow for a much larger diameter filling collar 22 to be incorporated in a container 10 without an attendant need to raise the axial height above that which is customarily in use in this category of the flexible container filling art.

Existing filling machinery may be modified simply to enable use of the method according to this invention by replacing the piercing tool of US 4,805,378 by the blunt end 44 as described above. The above embodiment differs from US 4,805,378 in that the rupturable closure shown therein is omitted, as is the incision tool in the filling apparatus used to pierce or cut the

membrane. Instead a blunt end or member is advanced from the filling head into the collar to separate a carefully formed temporary seal provided between the outwardly facing face of the flap where the collar joins the inner flange. The blunt end or member detaches the flap from the flange but does not puncture it, so creating upon withdrawal an entry path for liquid or flowable contents to enter the bag through the collar and opening, the flap being attached as already disclosed in the references by partial welding to the flange or inside surface of the bag to retain it for full welding to the flange after the bag is filled.

The foregoing describes embodiments of the above invention and modifications made by those skilled in the art can be made thereto without departing from the scope of the present invention.