EP0236107B1

EP0236107B1 - Aseptic filling station

Info

Publication number: EP0236107B1
Application number: EP87301791A
Authority: EP
Inventors: Ian Mcarthur Anderson
Original assignee: Courtaulds Packaging Australia Ltd
Current assignee: LEFTRIGHT AUSTRALIA LIMITED; Visy Films and Laminates Pty Ltd; Wrightcel Ltd; Astrapak Ltd; Liqui Box Asia Pacific Ltd
Priority date: 1986-03-03
Filing date: 1987-03-02
Publication date: 1990-06-13
Anticipated expiration: 2007-03-02
Also published as: ES2016839B3; EP0236107A1

Description

This invention relates to a system of aseptic filling particularly for flexible containers made of synthetic plastic films.
Synthetic plastic flexible containers are useful for storing and dispensing wine, fruit juice and other liquid foodstuffs. Aseptic filling is a desirable mode of operation to ensure that the possibility of contamination or deterioration of the liquid product does not occur.
Generally aseptic filling is carried out by sterilising the flexible containers intemally and externally and maintaining the rilling equipment in a sterile room. It is very difficult to ensure that the equipment and containers are maintained in aseptic conditions and the time and expense involved is high.
US-A Patent 2 761 603 (Fairchild) discloses a method of aseptically filling rigid containers in which rigid containers are pre-sterilised and sealed with a rupturable seal or membrane. The Fairchild filling machine incorporated a filling tube and a sterilising head within the filling tube which pierces the rupturable seal and provides sterilising fluid axially of the filling tube to sterilise the internal surfaces of the filling head and the rupturable seal prior to its rupture.
US-A Patent 3 926 229 (Scholle) discloses an aseptic filling head in which the valve member for the product outlet incorporates an axial sterilising fluid conduit In similar manner to the Fairchild specification, the sterilising fluid is flushed into the product outlet of the filling head and the containers inlet after the filling operation.
European Patent Application EP-A 0 072 699 discloses an aseptic filling arrangement in which a valve member reciprocates in a fluid conduit to isolate an inlet opening from an outlet The valve member is also formed with a rupturing projection designed to puncture a sealed inlet to a container to be filled. The region of the conduit adjacent the junction with the container can be flushed with sterilising fluid through inlet and outlet passages. The fluid is injected into the region and subsequently removed.
Thus, a known sterilisable fluid product conduit defining an opening for allowing ingress and egress of degradable liquid contents includes a sterilisable product conduit defining two openings for allowing ingress or egress of degradable liquid contents, a portion of the conduit surrounding one of the openings being adapted to abut a container inlet, a valve member adapted for reciprocal movement within the conduit for isolating one opening from the other, the valve member carrying means for rupturing a sealing membrane located over the container inlet, resilient sealing means providing a seal between the conduit and the valve member between the two openings, at least one sterilising fluid inlet and at least one sterilising fluid outlet opening onto the conduit adjacent the said portion of the conduit which abuts the container inlet, the inlet and outlet being disposed laterally of the prduct flow.
It is an object of this invention to provide a method and apparatus for aseptic filling of flexible con- {ainers with liquids that provides a much better cleaning as well as sterilising action.
The present invention is characterised in that the inlet(s) extends substantially tangentially with respect to the adjacent wall of the conduit.
In another aspect of this invention a method of aseptically filling containers comprising sterilising a sealed container which has a resealable inlet, maintaining the internal surfaces of a filling dispenser in a sterile state, bringing the closed inlet of the container into abutment with an outlet nozzle of the filling dispenser by means of a movable container support, introducing sterilising fluid into the space between the nozzle and the closed inlet in the direction laterally of product flow from the outlet nozzle into the container inlet and withdrawing it laterally, opening the inlet and filling the container, and resealing the inlet, is characterised by the sterilising fluid being introduced in a direction which is substantially tangential to the adjacent wall of the dispenser.
The present invention in a preferred embodiment is concerned with aseptically filling containers in which the container inlet has a heat sealable flap on one side of the inlet and is covered on the other side of the inlet by a rupturable closure which is ruptured to allow filling of the container and the container is finally sealed by heat sealing said flap.
This invention also provides in its preferred embodiment a system for aseptically filling and storing degradable liquid contents which comprises a flexible container having a sealed inlet, the inlet being capable of being opened and resealed, a fluid dispenser which incorporates a sterilisable product conduit having two openings for allowing ingress or egress of degradable liquid contents, a portion of the conduit, defining one of the openings, being adapted to abut a container inlet, a valve member adapted for reciprocal movement within the conduit for isolating one of the openings from the other, the valve member carrying means for rupturing a sealing membrane located over the container inlet, resilient sealing means providing a seal between the conduit and the valve member between the two openings, at least one sterilising fluid inlet and at least one sterilising fluid outlet opening into the conduit adjacent the opening which abuts the container inlet, the inlet(s) and outlet(s) being disposed laterally of product flow, means for sterilising the containers while the inlet is closed, container support means for bringing the container inlet into communicating engagement with a filling head portion of the conduit defining the one opening such that the one opening is closed by the container inlet, means for injecting the sterilising fluid into a recess in the said portion of the conduit, means for actuating the valve to aI- iow liquid to pass through the recess and fill the container, and means located external to the fixed filling head to reseal the inlet, the invention being characterised by the sterilising fluid being introduced in a direction which is substantially tangential to the adjacent wall of the dispenser.
This invention is particularly applicable to the apparatus described in European patent specification 56 701 and 72 699. The disclosures of those two specifications are incorporated herein by reference.
It can be seen that the need to sterilise the filling station environment and the exterior of the flexible container is eliminated by ensuring that the interior of the machine i.e. the fluid conduits and filling head and the interior of the container are sterile. Consequently only the exterior of the inlet seal and the external surface of the nozzle and the space between the nozzle and the inlet need be sterilised and this can be achieved as a preliminary step prior to filling.
Further, the provision of a simple valve member reciprocating within a conduit to serve the dual functions of closing the product outlet and puncturing a membrane on the container inlet simplifies the valve and filling head as proposed in European specifications 056 701 and 072 699 wherein the seal is a valve seal which restricts movement of the valve member.
The sterilisable product conduit of this invention preferably includes as the resilient sealing means a pair of annular edge seals projecting from the conduit wall and including between the pair of seals a sterilising fluid inlet which maintains the annular sealing space bounded by the valve member, conduit and seals in a sterile state.
The filling head of this invention can be used as such or if connected to an extraction pump can be used to extract product from sealed containers under aseptic conditions by bringing a filled and sealed container into abutment with the head, sterilising the recess and the container seal, rupturing the seal extracting product and closing the conduit.
The tangential disposition of the sterilising fluid inlet provides a much better cleaning action on the surface of the recess, the surface of the valve head and piercing tool and the surface of the rupturable membrane than can be achieved by the methods in US patents 2 761 603 (Fairchild) and 3 926 229 (Scholle). Similarly lateral extraction of sterilising fluid is also more efficient than the reverse axial extraction as taught in the prior art by Scholle and Fairchild.
Either heat, a permeating gas, or radiation such as electron beam, u.v. or preferably Gamma radiation is used to sterilise the sealed containers prior to filling. Hydrogen peroxide or steam is used to sterilise the surfaces and space between the outlet nozzle and the container closure.
When using the flexible container according to the above mentioned European patent applications it is possible to improve the ease of ensuring sterility of the interior of the container by providing a rupturable membrane cover over the outer opening of the collar. This ensures that the interior of the collar remains sterile. However, it is not essential to provide such a cover if the membrane seal on the inner end of the collar is adequate.
A preferred form of the invention will now be described, with reference to the drawings in which:

Fig. 1 is a schematic view of the container and collar;
Fig. 2 is a sectional view of the filling nozzle;
Fig. 3 is a cross-section through the head during the filling cycle;
Fig. 4 is a cross-section showing the sealing operation while the container is still in position at the filling head; and
Fig. 5 is a pian view of the filling head taken along the line 5-5- of Fig. 2.

Referring to Fig. 1, the bag - generally designated as 1 - comprises a wall 2 heat sealed at the periphery 3 to the lower wall 4. The flap 5 extends across an opening 7 in the flexible container wall 2 into which fits a collar 8. The flange 9 of collar 8 is heat sealed to the periphery 10 of the opening and the flap 5 is partly sealed to the flange of collar 8. As mentioned above the collar 8 can easily be secured to wall 2 by suitable machinery. The surface of flap 5 which faces the internal surface of wall 4 is non heat sealable therewith but the surface of flap 5 which faces flange 9 is heat sealable with that flange. Preferably flap 5 is a laminate of a heat sealable and non heat sealable material.
Across the outer opening of collar 8 is a rupturable membrane 41 which is either integrally formed during the moulding of collar 8 or is heat sealed thereto during the operation of attaching the collar 8 to the container wall 2. Apart from the membrane 41 the container and collar is as described in US-A patent no. 4 257 535.
The filling apparatus is a modified version of that described in EP-A 56 701.
The filling head comprises a general body section 20 which includes a liquid inlet channel 21 closed by the valve member 22. This valve member 22 extends within the body section 20 and serves the dual function of valve member and piercing tool. The valve member 22 seals the product outlet when in contact with the double elastomeric seals 49 and 50. In order to ensure an aseptic seal a positive steam pressure is maintained in the annular space 53 through steam from inlet 51. Steam is removed from space 53 through outlet 52. A piercing tool 25 is attached to the lower portion of the valve head 22.
When the valve member 22 is in its closed position the liquid inlet channel 21 is sealed and the seals 29, 30, 49 and 50 ensure that no liquid can escape once the valve member 22 is closed.
The sterilising fluid inlet 44 and outlet 45 are connected to the nozzle recess 46 below the seals 49 and 50. The number of inlets 44 and outlets 45 can be varied. By positioning several inlets tangentially about the periphery of recess 46 an efficient cleaning action can be achieved. One large exhaust port 45 is usually sufficient
In Fig. 3 the complete flexible container is illustrated being held against the body section 20 by clamps 33. These clamps 33 grip the collar 8 and a trapdoor 36 supports the flexible container but provides a sufficient gap to enable liquid to flow through collar 8 past flap 5 and into the body of the flexible container 1. The support of trapdoor 36 is required to ensure that the pressure of the liquid during the filling does not rupture the container, or heat sealable flap.
The sequence of operations is that initially a flexible container 1, is taken by clamps 33 and lifted into alignment with the filling head such that collar 8 and membrane 41 abut tightly against the seal 31 on the body section 20. After contact is made between body section 20 and membrane 41 sterilising fluid (either gas or liquid such as steam) is passed in to the recess 46 via inlet 44 and sterilises the inner surfaces of the recess and valve member 22, piercing member 25 and the surface of membrane 41. Subsequently the sterilising fluid is withdrawn through outlet 45.
After completion of the sterilisation step valve member 22 rises to open the product inlet 21 to enable filling of the flexible container to occur. A positive steam pressure is maintained in steam inlet 51 to outlet 52 to keep them clear of the product. The membrane 41 is ruptured during filling by the pressure of the liquid and is subsequently not needed since flap 5 will provide the permanent seal for the filled container. Alternatively the membrane 41 may be ruptured by piercing member 25 prior to the opening of liquid inlet 21 by lowering valve member 22.
Upon the completion of filling the valve member 22 closes inlet 21 at the seals 49 and 50.
At this point the trapdoor 36 is withdrawn and the heat sealing member 35 is brought into contact with the flexible container and results in the welding of flap 5 to the flange 9 of the collar 8 to seal the flexible container. After sealing sterilising fluid is introduced through inlet 44 into recess 46 and collar 8 to remove all product from those areas and from the valve member 22 and piercing member 25. If desired this flushing cycle could commence prior to the heat sealing step and end after heat sealing is completed.
Subsequent to sealing, the filled flexible container is withdrawn from the filling head and if desired the tap can be inserted into collar 8.
Conventional pneumatics can be used to operate the movements of the valve member 22 and the clamps 33, the trapdoor 36 and sealing member 35. The timing and control of these components is simi- lady capable of being carried out by conventional control circuitry.
The filling machine head as contained in body 20 may also be utilised for the extraction of product from the sealed containers. Where large bulk containers are used for dispensing smaller quantities, an extraction pump connected to the product inlet 21 and the seal 5 can be broken by the piercing member 25 and product removed by evacuation through recess 46 and conduct 21. A sterilising step can take place prior to breaking the seal 5.
From the above it can be seen that this invention provides a simple means of ensuring aseptic filling of liquids.

Claims

1. A sterilisable product conduit defining two openings for allowing ingress or egress of degradable liquid contents, a portion of the conduit surrounding one of the openings being adapted to abut a container inlet (8), a valve member (22) adapted for reciprocal movement within the conduit for isolating one opening from the other, the valve member (22) carrying means (25) for rupturing a sealing membrane (41) located over the container inlet (8), resilient sealing means (49, 50) providing a seal between the conduit and the valve member (22) between the two openings, at least one sterilising fluid inlet (44) and at least one sterilising fluid outlet (45) opening onto the conduit adjacent the said portion of the conduit which abuts the container inlet (8), the or each inlet (44) and outlet (45) is disposed laterally of product flow, characterised in that the or each inlet extends substantially tangentially with respect to the adjacent wall of the conduit.

2. A product conduit as claimed in claim 1, in which the resilient sealing means comprise a pair of annular edge seals (49, 50) projecting from the conduit wall and including between the pair of seals (49, 50) a further sterilising fluid inlet (51) which maintains the annular sealing space bounded by the valve member, conduit and seals in a sterile state.

3. A method of aseptically filling containers comprising sterilising a sealed container (1) which has a resealable inlet (7), maintaining the internal surfaces of a filling dispenser in a sterile state, bringing the closed inlet (7) of the container (1) into abutment with an outlet nozzle of the filling dispenser by means of a movable container support (33), introducing sterilising fluid into the space between the nozzle and the closed container inlet (7) opening the inlet (7) and filling the container (1), and resealing the inlet (7), the sterilising fluid being introduced laterally with respect to product flow from the outlet nozzle into the container inlet (7) and withdrawn laterally, characterised by at least the inlet for the sterilising fluid being disposed in a direction which is substantially tangential to the adjacent wall of the dispenser.

4. A method as claimed in claim 3 in which the inlet (7) has a heat sealable flap on one side which is heat sealed to the interior side of the inlet after filling the container (1).

5. A method as claimed in claim 3 or 4 in which the inlet (7) is covered by a rupturable closure (41) which is broken to fill the container (1).

6. A method as claimed in any of claims 3 to 5 including introducing sterilising fluid into the space (46) between the nozzle and the closed inlet (7), withdrawing the sterilising fluid, and removing the container (1) from the dispenser.

7. A system for aseptically filling and storing degradable liquid contents which comprises a flexible container (1) having a seated inlet (7), the inlet (7) being capable of being opened and resealed, a fluid dispenser which incorporates a sterilisable product conduit having two openings for allowing ingress or egress of degradable liquid contents, a portion of the conduit, surrounding one of the openings, being adapted to abut a container inlet (⁷), a valve member (22) adapted for reciprocal movement within the conduit for isolating one of the openings from the other, the valve member (22) carrying means (25) for rupturing a sealing membrane (41) located over the container inlet (7), resilient sealing means providing a seal between the conduit and the valve member (22) between the two openings, at least one sterilising fluid inlet (44) and at least one sterilising fluid outlet (45) opening into the conduit adjacent the opening which abuts the container inlet, means for sterilising the containers while the inlet is closed, container support means (33) for bringing the container inlet (7) into communicating engagement with a filling head portion of the conduit defining the one opening such that the one opening is closed by the container inlet, means for injecting the sterilising fluid into a recess in the said portion of the conduit, means for actuating the valve member (22) to allow liquid to pass through the recess and fill the container, and means located external to the fixed filling head to reseal the inlet (7), the inlet(s) (44) and outlet(s) (45) being disposed laterally of product flow, characterised by at least the sterilising fluid inlet being disposed substantially tangentially with respect to the adjacent wall of the dispenser.

8. A system as claimed in claim 7 in which the sterilising fluid is introduced into the recess while the inlet (7) is closed by the membrane (41).