Note: Descriptions are shown in the official language in which they were submitted.
ASEPTIC FILLING STATION
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
sterilizing the flexible containers internally and
externally and maintaining the filling equipment in a
sterile room. It i5 very difficult to ensure that the
equipment and containers are maintained in aseptic
conditions and the time and expense involved is high.
USA Patent 2761,603 (Fairchild) disclosed a method
of aseptically filling rigid containers in which rigid
containers are pre sterilized and sealed with a rupturable
seal or membrane. The Fairchild filling machine
incorporates a filling tube and a sterilizing head within
the filling tube which pierces the rupturable seal and
provides sterilizing fluid axially of the filling tube to
sterilize the internal surfaces of the filling head and the
rupturable seal prior to its rupture.
US~ patent 392~,229 (Scholle) discloses an aseptic
filling head in which the valve member for the product
outlet incorporates an axial sterilizing fluid conduct. 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.
It is an object of this invention to provide a
method and apparatus for aseptic filling of flexible
containers with liquids.
To this end the present invention provides a system
for aseptically filling and storing degradable liquid
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contents which comprises: a) a flexible container having a
sealed inlet, said inlet being capable of being opened and
resealed; b) a fluid dispenser which incorporates a
sterilizable product conduit comprising (i) two openings for
allowing ingress or egress of degradable liquid contents
(ii) one of said openings being adapted to abut a container
inlet (iii) a valve member adapted for reciprocal movement
within said conduit for closing the other of said openings
(iv) said valve member carrying means for rupturing a
sealing membrane located over said container inlet (v)
resilient sealing means providing a seal between the conduit
and said valve members between said two openings (Yi ) at
least one sterilizing fluid inlet and at least one
sterilizing fluid outlet opening onto said conduit adjacent
the opening which abuts the container inlet, said inlets and
outlets being disposed laterally of produced flow; c) means
for sterilizing the containers while said inlet is closed;
d) container support means for bringing said container
inlet into engagement with said filling head suc.h that said
recess is closed by the container inlet; e) means for
injecting said sterilizing fluid into said recess; f)
means to open said container inlet ; g) means to actuate
said valve to allow liquid to pass through said recess, and
fill said container; and h) means located external to said
~ixed filling head to reseal said inlet.
In another aspect of this invention there is
provided a method of aseptically filling containers
characterized in the steps of: a) sterilizing sealed
containers which have a resealable inlet; b) maintaining
the internal surfaces of the filling dispenser in a sterile
state; c) bringing the closed inlet of the container into
abutment with the outlet nozzle of the filling dispenser by
means of a movable container support; d) introducing
sterilizing fluid into the space between said nozzle and
said closed inlet in a direction laterally of product flow
from said outlet nozzle into said container inlet and
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withdrawing it laterally. e) opening said inlet and filling
said container; f) resealing said inlet; g) introducing
sterilizing fluid in to the space between said nozzle and
said closed inlet in a direction lateral to product flow
from said outlet nozzle and withdrawing said stabilizing
fluid; h) removing said container from said 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
said inlet and is covered on the other side of said 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
lS embodiment a system for aseptically filling and storing
degradable liquid contents which comprises: a) a flexible
container having an inlet, said inlet being capable of being
sealed by heat sealing a heat sealable flap onto one side of
the inlet opening and inçorporating over its other inlet
opening a rupturable closure; b) a fluid dispenser which
incorporates a sterlizable product conduit comprising
(i) two openings for allowing ingress or egress of
degradable liquid contents (ii) one of said openings being
adapted to abut a container inlet (iii) a valve member
adapted for reciprocal movement within said conduit for
closing the other of said openings (iv) said valve member
carrying means for rupturing a sealing membrane located over
said container inlet (v) resilient sealing means providing a
seal between the conduit and said valve members between said
two openings (vi) at least one sterilizing fluid inlet and
at least one sterili2ing fluid outlet opening onto said
conduit adjacent the opening which abuts the container
inlet:, said inlets and outlets being disposed laterally of
produced ~low; c) means for sterilizing the containers while
closed with said rupturable closure; d) container support
means for bringing said container inlet into engagement with
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said filling head such that said recess is closed by said
rupturable closure; e) means for injecting said sterilizing
fluid into said recess; f) means to actuate said valve to
allow liquid to pass through said recess, and fill said
container; and g) heat sealing means located external to and
below the fixed filling head.
This invention is particularly applicable to the
apparatus described in European patent specification 56701
and 72699. This disclosure of those two specifications are
incorporated herein by reference.
It can be seen that the need to sterilize 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 sterilized 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 056701 and 072699
wherein the seal is a valve seat which restricts movement of
the valve member.
The sterilizable 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 sterilizing 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 brinqing a filled and sealed container into
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abutment with the head, sterilizing the recess and the
container seal, rupturing the seal extracting product and
closing the conduit.
An important aspect of this invention is the
provision of sterilizing fluid inlets disposed laterally of
product flow through the recess. Preferably the inlets are
tangential to the circular recess wall to provide a swirling
motion of the sterilizing fluid within the recess. This
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 provided
by axial flow of the sterilizing fluid as taught in US
patents 2751,603 (Fairchild) and 3926,229 (Scholle).
Similarly lateral extraction of sterilizing fluid is also
more efficient than the reverse axial extraction as taught
in the prior art by Scholle and Fairchild.
Either heat, a permeable gas, or radiation such as
electron beam, u.v. or preferabl~Gamma radiation is used to
sterilize the sealed containers prlor to filling. Hydrogen
peroxide or ~team is used to sterilize the surfaces and
space between th~ outlet nozzle and the container closure.
When using the flexible container according to the
above mentioned 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. ~owever, it is not
essential to provide such a cover if the membrane seal on
the inner end of the collar is adequate.
~ preferred form of the invention will now be
described, with reference to the drawings in which figure 1
is a schematic view of the container and collar, figure 2 is
a sectional view of the filling nozzle, figure 3 is a
cross-section through the head during the filling cycle,
figure 4 is a cross-section showing the sealing operation
while the container is still in position at the filling
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head, and figure 5 is a plan view of the filling head taken
along the line 5-5 of figure 2.
Referring to Figure 1, the bag - ~enerally
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 g 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 a 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 USA patent no. 4257535.
The filling apparatus is a modified version of that
described in European patent application 82 300 1 458.
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 outlet channel 21 is sealed and the seals 29, 30,
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49 and 50 ensure that no liquid can escape once the valve
member 22 is closed.
The sterilizing fluid inlet 44 and outlet 45 are
connected to the noxzle 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 figure 3 the complete flexible container is
illu.strated being held against the body section 20 by clamps
33. These clamps 33 grip the collar a 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
sectlon 20. After contact ~s made between body section 20
and membrane 41 sterilizing fluid ~either gas or liquid such
as ~team) is passed in to the recess 46 via inlet 44 and
~terilizes the inner surfaces of the recess the valve member
22, piercing member 25 and the surface of membrane 41.
Subsequently the sterilizing ~luid is withdrawn through
outlet 45.
After completion of the sterilization step valve
member 22 rises to open the pr~duct inlet 21 to enable
filling of the flexible container to sccur. 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 fillin~ 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
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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.
~fter sealing sterilizing 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 fill2d 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 similarly 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
dispen~ing 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 sterilizing 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.
