Technical field
[0001] The present invention relates to the sealing of containers in applications wherein
vacuum can develop inside the containers and more particularly can mechanically deform
the containers or wherein an overpressure can build up inside the containers and more
particularly can mechanically deform the containers. The invention is more especially
useful for hermetically sealing containers in hot-fill applications, or for hermetically
sealing containers that have been sterilized, notably by carrying out a pasteurization
process or a retort process. In this technical field, the invention relates to a novel
venting closure that is suitable for sealing a container and avoiding pressures (vacuum
pressures or overpressures) inside the container, and in particular pressures that
could mechanically deform the container, and to a process for filling and sealing
a container.
Prior art
[0002] In a hot-filling process, a container is filled with a commodity such as for example
a liquid, while the commodity is at an elevated temperature. For example for liquids,
such as juices, the temperature is typically between 68°C and 96°C, and is usually
around 85°C. When packaged in this manner, the high temperature of the commodity also
sterilizes the container at the time of filling. The container is not completely filled,
but the filling is generally performed in such a way to keep a headspace with air
inside the container.
[0003] After being hot-filled, the container is capped and allowed to reside at generally
the filling temperature for a few minutes and is then actively cooled prior to transferring
to labeling, packaging, and shipping operations.
[0004] When the product in the container is liquid or semi-liquid, this cooling reduces
the volume of the product inside the container. This product shrinkage phenomenon
results in the creation of a vacuum within the container. This vacuum is even more
important when a headspace is existing.
[0005] Plastic containers and in particular PET (Polyethylene Terephthalate) containers
are now widely used for storing various commodities, and in particular food products,
liquids, etc... In particular, manufacturers and fillers, as well as consumers, have
recognized that PET containers are lightweight, not expensive, can be manufactured
in large quantities and can be recycled.
[0006] When a deformable container, like for example a plastic container, and more particularly
a PET container, or like for example a cardboard container, is being hot filled, if
the vacuum pressures generated inside the container is not controlled or otherwise
accommodated, these vacuum pressures can result in unwanted severe deformations of
the container, which leads to either an aesthetically unacceptable container or one
that is unstable. Moreover, said vacuum pressures detrimentally increase the opening
torque that is necessary for removing the closure cap and opening the container.
[0007] It has been proposed in the prior art to accommodate vacuum pressures in hot-fill
plastic containers by incorporating deformable structures in the container wall and/or
base
[0008] Plastic hot-fill containers incorporating such deformable structures are for example
described in the following publications:
U.S. Patents 5,005,716 ;
5,503,283 ;
6,595,380 ;
6,896,147 ;
6,942,116 ; and
7,017,763, and
PCT application WO 2001/014759. In these publications, a deformable structure to at least partially compensating
the volume reduction that occurs after capping and during cooling of a hot-filled
product, is located in the base of the container. More particularly, in
PCT application WO 2011/014759, the movable container base includes a central push-up portion and is designed to
move up to accommodate internal vacuum pressures.
[0009] Plastic hot-fill containers are also described for example in the following publications:
European patent application
EP 1 947 016 and
U.S. Patents 5,222,615 ;
5,762,221 ;
6,044,996 ;
6,662,961 ;
6,830,158. In these publications, a deformable portion, to at least partially compensating
the volume reduction that occurs after capping and during cooling of a hot-filled
product, is located in the shoulder part of the container.
[0010] Plastic hot-fill containers are also described for example in the following publications
:
U.S. Patents 5,092,475 ;
5,141,121 ;
5,178,289 ;
5,303,834 ;
5,704,504 ;
6,585,125 ;
6,698,606 ;
5,392,937 ;
5,407,086 ;
5,598,941 ;
5,971,184 ;
6,554,146 ;
6,796,450. In these publications, the deformable portions, to at least partially compensating
the volume reduction that occurs after capping and during cooling of a hot-filled
product, are located in the sidewall of the main body of the container, and are commonly
referred as vacuum panels. In this case, the volume compensation can be advantageously
increased.
[0011] The hot filling process is acceptable for commodities having a high acid content,
but is not generally acceptable for non-high acid content commodities. For non-high
acid commodities, pasteurization and retort are generally the preferred sterilization
processes.
[0012] Pasteurization and retort are both processes for cooking or sterilizing the contents
of a container after filling. Both processes include the heating of the contents of
the container to a specified temperature, usually above approximately 70°C for a specified
length of time (for example 20 - 60 minutes). Retort differs from pasteurization in
that retort uses higher temperatures to sterilize the container and cook its contents.
Retort also generally applies elevated air pressure externally to the container to
counteract pressure inside the container.
[0013] In pasteurization and retort processes, if the container is hermetically closed during
the heating phase, an overpressure can build up inside the container and can deform
the container. Vacuum pressures can also develop inside the plastic container during
the cooling phase of the container, which can also result in unwanted deformations
of the container.
[0014] One first solution to avoid the development of pressures (vacuum pressures or overpressure)
inside a deformable container in hot-fill applications or in pasteurization and retort
processes is to perform the sealing of the container in two sequential steps. In a
first step, once the container is being filled with a hot product, a closure cap is
for example positioned onto the container, but the container is not hermetically sealed,
and air from the outside can freely enter inside the container, thereby avoiding the
development of internal vacuum during the cooling phase of the product or air can
freely escape outside the container, thereby avoiding the development of internal
overpressures during the heating phase of the product. Once the product inside the
container is sufficiently cold, the container is hermetically sealed by the closure
cap.
[0015] In a second solution disclosed in
US patent n° 7,748, 525, it has been proposed to use a closure cap that is designed in such a way to reduce
the volume of the head space. In this solution, air from the outside can still freely
enter inside the container during the cooling phase.
[0016] A major problem of these first and second solutions is that the air entering in the
container during the cooling phase can transport contaminating agents, such as for
example dust, bacteria and can detrimentally contaminate the product stored in the
container.
[0017] To solve this problem, it is has been proposed, notably in
PCT application WO 2009/117328, a closure cap having a gas permeable vent with an integral sealing means that is
externally activable by a nonmechanical means, to effect hermetic sealing of the container
after filling and cooling. More particularly, the gas permeable vent is a non-fusible
porous matrix or membrane and comprises a porous fusible material that can hermetically
close the non-fusible porous matrix when it is melted, for example by using an electromagnetic
induction source. The sealing of the container is performed in two steps. In a first
step, once the container is being filled with a hot product, the container is closed
by the said closure cap. During the cooling phase, vacuum inside the container is
relieved by air from the outside that enters inside the container though the non-fusible
porous matrix or membrane acting as a filter. Once the product inside the container
is sufficiently cold, the porous fusible material is activated, for example by means
of an electromagnetic induction source, and is melted in such a way to hermetically
seal the non-fusible porous matrix or membrane, thereby hermetically sealing the container.
[0018] This technical solution of a closure cap having heat-sealable gas permeable vent
involves the manufacturing of a complex and costly closure cap and involves the use
of a specific equipment for melting the porous fusible material. Moreover, the presence
of the porous fusible material in the closure cap can be prejudicial for the recycling
of the closure cap, especially if the porous fusible material comprises suitable energy
absorbing material in the form of metallic particles that can be inductively heated
for melting the porous fusible material.
Objective of the invention
[0019] An objective of the invention is to propose a novel technical solution for sealing
a container in applications wherein pressures (vacuum pressures or overpressures)
can develop inside the container and in particular can mechanically deform the container,
which solution avoids the development of such internal pressures and also reduces
the risk of contamination of the inside of the container, and which solution also
avoids the use of a special equipment for heat-sealing a venting closure as disclosed
in
PCT application WO 2009/117328.
[0020] Another objective of the invention is to propose a venting closure that can be easily
recycled.
Summary of the invention
[0021] To achieve these objectives, a first object of the invention is a venting closure
as defined in claim 1.
[0022] Another object of the invention is the container and venting closure of claim 17
[0023] Another object of the invention is the process for filing and sealing a container
as defined in claim 25.
Brief description of the drawings
[0024] The technical characteristics and advantages of the invention will appear more clearly
on reading the following detailed description of several embodiments of the invention,
which detailed description is made by way of non-exhaustive and non-limiting examples,
and with reference to the appended drawings, as follows:
- Figure 1 is a longitudinal cross section view of a venting closure according to a
first embodiment, fitted onto the neck finish of a container, in a first closing position
wherein the development of internal vacuum inside the container is prevented.
- Figure 2 is a cross section of the venting closure in the plane II-II of figure 1.
- Figure 3 is a longitudinal cross section view of the neck finish and venting closure
of figure 1, in a sealing position wherein the container is hermetically sealed.
- Figures 4, 6 and 8 are longitudinal cross section views of a venting closure according
respectively to a second, third and fourth embodiments, fitted onto the neck finish
of a container, in a first closing position wherein the development of internal vacuum
inside the container is prevented.
- Figures 5, 7, and 9 are longitudinal cross section views of the neck finish and venting
closure of respectively Figure 4, Figure 6, and Figure 8 in a sealing position wherein
the container is hermetically sealed.
Detailed description
[0025] Some preferred embodiments of the invention are discussed in detail below. While
specific exemplary embodiments are discussed, it should be understood that this is
done for illustration purpose only. A person skilled in the art will recognize that
other container designs or container dimensions can be used without parting from the
spirit and scope of the invention.
[0026] In reference to figure 1, a closure 1 A of the invention is fitted onto a standard
neck finish 2 of a deformable container C comprising a top opening 20 (container mouth),
like for example a bottle neck finish. This top opening 20 of the neck finish 2 is
knowingly used for filling the container with a product and/or for pouring the product
outside the container. In this particular embodiment, the closure 1 is a cap screwed
on the container neck finish 2. In another variant, the closure 1 could be snapped
on the container neck finish 2.
[0027] The material and the shape of the container C are not important. In particular the
container can be made from any material that makes the container deformable at ambient
temperature under an internal pressure (vacuum pressure or overpressure) generated
inside the container C. In particular, the container C can be for example any plastic
container or any cardboard container. More particularly, the container is not made
of glass.
[0028] The container can be for example a bottle-shaped container, a flask, a jar, a tube,
a bag, a pouch.
[0029] Within the scope of the invention, the deformable container C can be rigid, semi
rigid or flexible. The container C may be either of a monolayer construction or a
multilayer construction.
[0030] When the container C is made of plastic, suitable thermoplastic materials which may
be used, as a layer or part of one or more layers in either monolayer or multilayer
containers, include polyesters, and in particular polyethylene terephtalate (PET),
polyolefins (including but not limited to polypropylene(PP) and polyethylene (PE)),
polyetheresters, polyesteramides, polyurethanes, polyimides, polyureas, polyamideimides,
polyamides, polyacrylates, polyphenyleneoxide, phenoxy resins, epoxy resins, polystyrene
(PS), polyvinyl (including but not limited to polyvinyl chloride (PVC), polylactic
acid (PLA), polyethylene-furanoate (PEF), homo or copolymers thereof, or combinations
thereof.
[0031] The container C can be manufactured by using any method known in the art, including
but not limited to injection moulding, injection blow moulding (IBM), injection stretch-blow
moulding (ISBM), extrusion blow moulding, thermoforming, rotational moulding, folding.
[0032] The container can be a biaxial stretched plastic containers that is heat resistant,
for example a heat-set ISBM container or a double blown ISBM container.
[0033] The closure 1 A comprises a non-porous shell 10, in the form of a cap, which is single
piece, made from any material than makes the shell 10 substantially impermeable.
[0034] In certain embodiments, the material of the closure shell 10 can be for example any
known thermoplastic material that can be moulded in a mould, and more particularly
any known thermoplastic material that can be processed by injection or compression
moulding. Preferably, the closure shell 10 can be made from a polyolefin, like for
example polypropylene, polyethylene, polyethylene terephthalate, homo or copolymer,
or combinations thereof. A good candidate for making the closure shell 10 is HDPE
(High Density Polyethylene).
[0035] This shell 10 comprises a top wall 100 surrounded by a skirt 101. The top wall 100
comprises an outer face 100b and an inner face 100a that is intended in use to be
oriented toward the inside (IN) of the container C. The skirt 101 extends transversally
to the top wall 100, and defines a housing 102 with the inner face 100a of the top
wall 100.
[0036] For example, but not necessarily, the top wall 100 can form a disc and the skirt
101 can be cylindrical.
[0037] In this particular example, the inner face 101 a of this skirt 101 comprises a screwing
thread 101 b that can cooperate with a screwing thread 21 of the neck finish 2 for
securing the closure 1A onto the neck finish 2.
[0038] The closure shell 10 also comprises a seal 103 positioned inside the housing 102,
and adapted to hermetically seal the top opening 20 of the container neck 2 when the
closure 1A is screwed on the container in the sealing position of figure 3.
[0039] More particularly, in this example, the seal 103 is a deformable and annular sealing
lip 103A formed on the inner face 101 a of the top wall 100.
[0040] This deformable sealing lip is extending on the whole periphery of the top wall 100.
[0041] Pursuant to the invention, the closure 1A also comprises a porous venting medium
104 that is gas permeable. Said porous venting medium 104 is distinct from the seal
103.
[0042] Suitable materials for the porous venting medium 104 include any material that is
gas-permeable, but which provides an effective barrier for isolating against migration
of solids and liquids therethrough, including for example bacterial, viral, particulate,
and other such material penetration.
[0043] Examples of porous venting medium 104 include, but are not limited to polymeric films
or membranes, porous pads, papers, nonwovens, and combinations thereof.
[0044] In certain embodiments the porous venting medium 104 can be made from a polymer such
as a polyolefin or fluorinated polyolefin. A list of suitable polyolefin includes,
but is not limited to, polyethylenes polypropylenes, ethylene/propylene copolymers,
polybutylenes, polymethylpentenes, copolymers thereof and combinations thereof. A
particularly suitable fluorinated polyolefin is polytetrafluoroethylene (PTFE), in
particular microporous PTFE or expanded porous PTFE (ePTFE).
[0045] In certain other embodiments the porous venting medium 104 can be made from ethylene
copolymers including, but not limited to, ethylene/vinyl acetate copolymers, ethylene/vinyl
alcohol copolymers and polyvinyl acetates as well as alloys, mixtures and combinations
thereof.
[0046] The porosity of the porous venting medium 104 will depend of the size of the contaminants
(dust, particles, bacteria, etc.) that have to be blocked by the porous venting medium
104 or trapped inside the porous venting medium 104.
[0047] The smaller the pore size is, the more reliable the barrier performance is. In certain
embodiments the porous venting medium 104 can have for example a pore diameter range
of 0.01µm to 350µm, with 0.05 µm to 2.0 µm preferred and 0.10µm to 0.20µm most preferred.
[0048] In certain embodiments, the porous venting medium 104 can be hydrophobic or hydrophilic;
[0049] More particularly, in reference to figure 1, this porous venting medium 104 is positioned
inside the housing 102 defined by the shell 10, and is thereby protected by the shell
10 against deterioration.
[0050] In the particular example of figures 1 to 3, the porous venting media 104 is surrounded
by the seal 103, and the seal 103 is positioned on the outer side of the porous venting
media 104 both in the closing position of figure 1 and in the sealing position of
figure 3.
[0051] More particularly, this porous venting medium 104 is an add-on porous venting medium,
more particularly of small thickness. Add-on porous venting medium 104 of higher thickness
can also be used.
[0052] More particularly, in this example, this add-on porous venting medium 104 is attached
to the shell 10 by means of a supporting member 105.
[0053] In the variant of figure1, said supporting member 105 is part of the shell 10 and
is more particularly formed from the inner face 10a of the top wall 100.
[0054] More particularly, said supporting member 105 forms a sealing lip 105a around the
whole periphery of the porous venting medium 104.
[0055] More particularly, said supporting member 105 comprises air channels 105b (figures
1 and 2) for allowing air to pass through the supporting member 105 and positioned
on the outer side of the venting medium 104, i.e. in this variant between the top
wall 100 and the porous venting medium 104. These air channels 105b are preferably
distributed on the whole periphery of the porous venting medium 104 (figure 2).
[0056] When the closure 1A is screwed onto the container C in the closing position of figure
1, the porous venting media 104 is positioned outside the container and is closing
the top opening 20. Said top opening 20 of the container is not hermetically sealed,
but air A coming from the outside of the container C can penetrate into the container
C by passing through these air channels 105b and then necessarily at least through
the said porous venting medium 104.
[0057] In this particular variant, when the closure 1A is screwed onto the container C in
the closing position of figure 1, the sealing lip 105a, which is not permeable to
gas, is in seal contact with the inner face of the container neck finish 2, and air
coming from the outside of the container C is thus obliged to pass through these air
channels 105B and then necessarily at least through the said porous venting medium
104 before entering into the container C.
[0058] In the closing position of figure 1, the porous medium 104 acts as a filter for the
air coming from the outside of the container C and entering into the container C.
[0059] In the closing position of figure 1, air can also escape outside the container C
by passing through the porous venting medium 104.
[0060] The closure 1 A can be used for sealing a deformable container in any application
wherein vacuum can develop inside the container and more particularly can deform the
container. The closure 1A is more especially useful for hermetically sealing containers
in hot-fill applications, or for hermetically sealing containers that have been sterilized,
notably by carrying out a pasteurization process or a retort process.
[0061] In a hot-filling process, the container C is first hot-filled with a product. In
a pasteurization process or a retort process, the container C is first filled with
a product and the product inside the container is subsequently heated.
[0062] Then, in a hot-filling process or in pasteurization process or in a retort process,
the closure 1A is fitted onto the container C in the closing position of figure 1,
and the container C and the product are cooled down. During this cooling phase, air
A coming from the outside of the container C is passing necessarily through the porous
venting medium 104 (figure 1) and is filtered by the porous venting medium 104 before
entering inside the container into contact with the product stored inside the container.
This incoming and filtered air advantageously avoids the development of vacuum pressures
inside the container C while avoiding a contamination of the inside of the container
and of the product.
[0063] Additionally, in a pasteurization process or a retort process, during the heating
phase of the product, air can advantageously escape outside the container by passing
through the porous venting medium 104, thereby avoiding the development of an overpressure
inside the container.
[0064] Once, the container C and the product are sufficiently cold, the closure 1 is twisted
further with a sufficient torque to be brought into the final sealing position of
figure 3, wherein the seal 103 is in contact with the inner face of the container
neck finish 2, is mechanically deformed and is hermetically sealing the top opening
20 of the container C.
[0065] Moreover, as the development of vacuum pressures inside the container has been avoided,
the opening torque that is necessary to remove the closure 1 form the container is
advantageously less important, which renders the invention also useful for sealing
containers that are not deformable by internal vacuum pressures.
[0066] Figures 4 and 5 show another variant of closure 1 B wherein the porous venting media
104 has the form of a ring 104B and is positioned inside the housing 102 of the closure
shell 10 between the inner face 101 a of the skirt 101 and a retaining member 106.
The seal 103 of the closure 1 B is a deformable and annular sealing lip 103B formed
on the inner face 100a of the top wall 100. This annular sealing lip 103B is surrounded
by the porous venting media 104.
[0067] In use, when the closure 1 B is in the closing position of Figure 4, the porous venting
medium 104 is in a low position in contact with the container neck finish 2. The top
opening 20 of the container is not hermetically sealed, but air A coming from the
outside of the container C can penetrate into the container C by passing necessarily
at least through the said porous venting medium 104. This incoming air A is thus filtered
by the porous venting media and prevents the development of vacuum pressures inside
the container C. When the closure is moved in the sealing position of Figure 5, in
this particular case, by twisting sufficiently the closure onto the container neck
finish 2, the porous venting medium 104 is pushed and move upwards in a upper position
wherein it is no longer in contact with the neck finish 2, and the seal 103 is hermetically
sealing the top opening 20 of the container.
[0068] Figures 6 and 7 show another variant of closure 1C wherein the closure comprises
fastening means 101 c and is adapted to be snapped onto a container neck finish 2
in two positions (closing position of figure 6 before cooling and sealing position
of figure 7 after cooling). In this variant, the porous venting medium 104 is a disc
104C that is separated from the closure shell 10. The porous venting medium 104 could
also form a ring 104C
[0069] Figures 8 and 9 show another variant of closure 1 D wherein the closure is adapted
to be snapped onto a container neck finish 2 in two positions (closing position of
figure 8 before cooling and sealing position of figure 9 after cooling). In this variant,
the porous venting medium 104 is a compressible pad or ring 104D or the like, that
is attached to the inner face 100a of the top wall 100 of the closure shell 10. The
seal 103 is a deformable sealing lips 103D that is a part of the container, and that
is formed on the container, in particular on the upper wall of the neck finish 2.
When the closure 1 D is moved in the sealing position of Figure 9, the porous venting
medium 104 is being compressed.
[0070] As previously described for closure 1 A, closures 1 B, 1 C, and 1 D can be used for
sealing a deformable container in any application wherein vacuum can develop inside
the container and can deform the container and more especially for hermetically sealing
containers in hot-fill applications, or for hermetically sealing containers that have
been sterilized, notably by carrying out a pasteurization process or a retort process.
1. A venting closure (1A; 1 B; 1 C; 1 D) for sealing a container, said venting closure
comprises a shell (10) defining a housing (102), a porous venting medium (104) positioned
inside said housing (102) and a seal (103) distinct from the porous venting medium
(104) and positioned inside said housing (102), and said venting closure can be fitted
onto a container (C) in at least two positions : a closing position, wherein air (A)
coming from the outside of the container can enter into the container by passing necessarily
through the said porous venting medium (104), or air coming from the inside of the
container can escape outside the container by passing necessarily through the said
porous venting medium (104), and a sealing position, wherein the seal (103) is hermetically
sealing the container.
2. The venting closure (1 A ; 1 B; 1 C; 1 D) of claim 1, wherein the porous venting medium
(104) is surrounded by the seal (103).
3. The venting closure (1B) of claim 1, wherein the seal (103) is surrounded by the porous
venting media (104).
4. The venting closure (1B) of claim 3, wherein the porous venting medium (104) forms
a ring.
5. The venting closure of any one of the previous claims, wherein the porous venting
medium (104) is attached to the closure shell (10).
6. The venting closure of claim 5, wherein the porous venting medium (104) is attached
to the closure shell (10) by means of a supporting member (105) and wherein said supporting
member (105) comprises one or several air channels (105b) for allowing air to pass
through the supporting member (105) and positioned on the outer side of the porous
venting medium (104), and a sealing lip (105a) around the whole periphery of the porous
venting medium (104).
7. The venting closure of claim 6, wherein the supporting member (105) is an integral
part of the closure shell (10).
8. The venting closure of any one of claims 1 to 7, wherein the porous venting medium
(104) is not attached to the closure shell (10).
9. The venting closure of any one of the previous claims, wherein the seal (3) is a deformable
sealing lip (103A ; 103B) that is an integral part of the closure shell (10).
10. The venting closure of any of any one of the previous claims, wherein the shell (10)
comprises a top wall (100) surrounded by a skirt (101).
11. The venting closure of claims 9 and 10 wherein the sealing lip (103A; 103B) is formed
on the inner face (100a) of the top wall (100).
12. The venting closure of any of any one of the previous claims, wherein the shell (10)
is a plastic cap, and preferably a plastic molded cap.
13. The venting closure of any one of the previous claims, wherein the shell (10) comprises
a thread (101 b) in order to be screwed onto the neck finish (2) of a container in
the said closing positon and in the said sealing position, or fastening means (101
c) in order to be snapped onto the neck finish (2) of a container in the said closing
position and in the said sealing position.
14. The venting closure of any one of the previous claims, wherein the porous venting
medium (104) has a pore diameter in the range of 0.01µm to 350µm.
15. The venting closure of any of the previous claims, wherein the porous venting medium
(104) has a pore diameter in the range 0.05µm to 2.0 µm, and more preferably in the
range 0.10µm to 0.20µm.
16. The venting closure of any of the previous claims, wherein the porous venting medium
(104) comprise a microporous polymer.
17. A container (C) and a venting closure of any one of the previous claims.
18. The container and venting closure of claim 17, wherein the container can be deformed
by internal pressures inside the container (C).
19. The container and venting closure of claim 17 or 18, wherein the container is made
of plastic.
20. The container and venting closure of any one of claims 17 to 19, wherein the container
is not made of glass.
21. The container and venting closure (1 D) of any one of claims 17 to 20, wherein the
seal (103) is an integral part of the container.
22. The container and venting closure of claim of any of claims 17 to 21, wherein the
porous venting medium (104) is not compressed by the shell both in the closing position
and in the sealing position.
23. The container and venting closure of claim of any of claims 17 to 21, wherein the
porous venting medium (104) is compressed by the shell in the sealing position.
24. The container and venting closure (1A ; 1 B; 1C ; 1 D) of any one of the claims 17
to 23, wherein at least in the closing position of the venting closure cap, and preferably
also in the sealing position, the porous venting media (104) is positioned outside
the container.
25. A process for filing and sealing a container, comprising the following sequential
steps :
(i) hot-filling the container (C) with a hot product or filing the container (C) with
a product and heating the product,
(ii) closing the container with a closure comprising a seal (103) and a porous venting
medium (104) in such a way that air (A) coming from the outside of the container can
enter into the container by passing necessarily at least through the said porous venting
medium (104), or air coming from the inside of the container can escape outside the
container by passing necessarily through the said porous venting medium (104),
(iii) cooling down the container and product,
(iv) once the container and product are sufficiently cold, moving the closure to a
position wherein the seal (103) of the venting closure is hermetically sealing the
container.
26. The process of claim 25 wherein the container and venting closure are the ones defined
in any one of claims 17 to 24.
27. The process of any one of claims 25 to 26, wherein the container (C) is hot-filled
during step (i) with a hot product at a temperature above 60°C, and preferably above
80°C.
28. The process of any one of claims 25 to 27, wherein the product is heated during step
(i) for sterilizing or pasteurizing the product.