Note: Descriptions are shown in the official language in which they were submitted.
v
CA 02384279 2002-03-07
Process for closing a container and closure for this
purpose
Description
The invention relates to a process for closing
a container according to the preamble of Claim 1 and to
a closure serving for this purpose according to-the
preamble of Claim 11.
Processes of the type mentioned here are known.
If it is intended; for example in a filling plant, for
containers such as bottles, canisters or the like to be
filled with a liquid and then closed by a closure, then
the containers, for this purpose, are first of all
removed from a feed device, for example a magazine, and
fed to a filling installation by means of a conveying
device. In the filling installation, a filling valve,
through which the liquid is filled into the container,
is lowered over the mouth region of the container. The.
filled container is then fed to a closing installation,
in which the mouth region of the container is closed by
a closure which is likewise removed from a magazine and
fed via a conveying device. The closure operation takes
place in various ways, depending on the design of the
closure. Thus, in the case of a metallic closure, a
closure blank is fitted onto the mouth region of the
container and then, by means of a shaping tool, adapted
in shape to the mouth region of the container, whereas;
in tha case of a plastic closure; the latter, once.
fitted onto the mouth region of the container, is
screwed onto the mouth region by means of a screwing
tool.
The process may also be used analogously for
the operation of filling containers with granular or
pulverulent solids.
Although both the containers and the closures
are cleaned and, if appropriate, even disinfected
before being introduced into the magazine - or have
been cleaned already - the situation where the mouth
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region of the container is contaminated by contents
during feeding to the filling installation, in
particular during the filling operation, or else during
feeding to the closure installation or during the
closure operation cannot be avoided in the case of the
process described. Up until now, between the operations
of filling and closing the container, the mouth region
of the container has been subjected to a cleaning
operation, in the case of which, for example, a
flushing-liquid jet is directed onto the mouth region
of the container and the latter is possibly then dried
by a blowing means or said container is cleaned by
means of a brush or a cloth in order to remove the
contents deposited there. The disadvantage with this
procedure is that droplets of flushing liquid, broken-
off bristles from the brush or fluff from the cloth can
pass into the interior of the container, thus
contaminating the container contents. In the case of
granular container contents, this procedure may result
in flushing liquid which has penetrated into the mouth
region of the container beginning to dissolve the
container contents in the mouth region of the
container, which results in the container contents
forming lumps.
Moreover, the prior art contains a W de range
of different closures for containers. In particular,
multi-part container closures are also known. Thus, iri
particular in the case of drinks bottles, use is made
of two-part pull-open closures which comprise a sealimg
sheet stretched over the mouth region of the container
as well as an outer closure provided with a pull-open
tab. If use is made of these closures for closing
containers by the process just discussed, the
disadvantages which have already been described arise
here as well.
The object of the invention is thus to propose
a process for closing a container which allows
hygienically satisfactory closure of the container, and
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also to develop a closure which is suitable for this
purpose.
In order to achieve this object, the invention
proposes a process for closing a container by means of
a closure which has a closure cap and a sealing device,
which comprises a sealing cap. During the operation of
closing the container, the mouth region of the
container is cleaned between the operations of fitting
the sealing cap and fitting the closure cap. The
closure cap and the sealing cap, which are separate
before the operation of closing the container and are
also fitted onto the container in separate process
steps, are thus brought together for the first time
during the operation of closing the container. First of
all the sealing cap is fed to the container and fitted
onto the mouth region of the same. Since the sealing
cap closes the mouth region of the container,
penetration of substances which contaminate the
container contents is reliably avoided during the
operation of cleaning the container mouth, and the
container content thus cannot be adversely affected by
the cleaning operation.
A preferred variant makes provision for the
mouth region of the container to be cleaned in that it
is sprayed, brushed off and/or wiped off. It is
possible, moreover, to subject the mouth region to the
action of a drying gas. The various.possible cleaning
methods, individually or in combination, ensure optimum
cleaning of the-mouth region.
In a preferred variant, provision is made for
the closure cap to consist of metal and for the process
to comprise fitting of the sealing insert onto the.
mouth region, cleaning the mouth region, fitting the
closure cap onto the mouth region and shaping the
closure cap. This variant constitutes the adaptation of
the process according to the invention to a metallic
closure cap. Following the operations of fitting the
sealing cap, cleaning and, if appropriate, drying, a
closure-cap blank is fitted onto the mouth region and
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is shaped into the finished closure cap. During the
shaping operation, for example, the thread of the
closure or else grooves are made, the closure being
easier to open as.a result.
A further preferred variant makes provision for
the closure cap to be designed as a screw cap and to
consist of plastid and for the process to comprise
fitting the sealing insert onto the mouth region,
cleaning the mouth region, fitting the closure cap onto
the mouth region and screwing the closure cap onto the
mouth region. This variant of the process is adapted to
the screw cap consisting of plastic. The screw cap is
thus already in the finished state before it is fitted
onto the mouth region of the container and screwed on.
It is further preferred if - in the case of the
metallic closure cap - the sealing insert is fitted by
means of a first fitting tool, the mouth region is
cleaned by means of a cleaning tool, preferably a
flushing nozzle and/or an automatic brush and/or a
wiping means, the mouth region is dried by means of a
drying tool, preferably a blowing nozzle, the closure
cap is fitted by means of a second fitting tool, and
the closure cap is shaped by means of a shaping tool,
preferably a deep-drawing tool, in particular a plunger
and thread rolls. In the case of this variant, all the
steps of the process are carried out by means. of tools
developed. for this purpose. The process may thus be
carried out in a fully automatically functioning
filling line.
In addition, for the case of a plastic closure
cap formed as a screw cap, provision is preferably made
for a tool also to be used for the operation of
screwing the screw cap onto the mouth region: It is
thus also possible for plastic screw caps to be fitted
in a fully automatic filling line.
In order to achieve said object, the invention
also proposes a closure in the case of which the
sealing insert is designed as a sealing cap and has at
least one retaining. means interacting with the
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container. Designing the sealing insert as the sealing
cap requires it to be adapted in size to the mouth
region of the container, that is to say the dimensions
of the sealing insert are selected such that, following
the operation of fitting the sealing insert onto the
mouth region of the container, the latter is closed and
the sealing insert or the sealing cap is retained
securely. The term "sealing cap" indicates that the
sealing insert itself assumes properties of a closure
cap, namely the closure property. The retaining means,
which interacts in particular with the mouth region of
the container, allows the sealing insert to be
supported in the mouth region, that is to say slipping
of the sealing insert when subjected to the action of
pressure from the inside or from the outside is
avoided. Being subjected to the action of pressure may
be brought about, inter alia, by being cleaned by being
sprayed with the cleaning liquid or being dried by
being subjected to the action of the cleaning gas
flowing out of a blowimg nozzle. In both cases; the
sealing insert is retained securely in the mouth region
of the container.
In the case of a preferred exemplary embodiment
of the closure, provision is made for the retaining
means to be designed as a web which runs all the way
around the sealing cap and extends essentially
perpendicularly away from the wall of the Baling
insert. This design of the retaining means provides the
largest possible surface area for the interaction of
the sealing cap with the containe r. In this case, the
sealing cap is retained by clamping in the mouth region
of the container. Depending on the three-dimensional
shape of the sealing cap, this clamping may take place
on the inside of the mouth region and on the outside
thereof.
Also preferred is an exemplary embodiment of
the closure which has a latching means, also referred
to as a bead, which is designed as a peripheral
protrusion and which can retain the sealing cap. The
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latching means makes it possible for the screw cap and
the sealing cap to be connected with a form fit during
the shaping operation, in the case of the screw cap
being metallic, and during the screwing-on operation,
in the case of the screw cap being plastic. It is also
the case that said connection is not released when the
closure is removed by a consumer, that is to say the
consumer can remove the closure cap and the sealing cap
at the same time from the mouth region of the
container. When the container is closed again, the
sEaling cap is then already integrated firmly in the_
closure cap.
Furthermore, provision is preferably made for
the sealing cap to have a bottom, an encircling wall
which extends from the bottom, and a flange which
adjoins the wall and is provided with a bent-down
border. This configuration of the sealing cap provides
further surfaces which can interact with the mouth
region of the container. For example, it is possible
for the flange to butt against the top side of the
mouth region, and for the bent-down border of the
flange to. butt against the outside of the mouth region,
of the container. This configuration of the flange thus
further improves the secure retention of he sealing
cap in the mouth region, as well as the sealing
properties thereof.
Moreover, an exemplary embodiment of a closure
in the case of which the bottom of the sealing cap has
a first base surface and a second base surface, which
extends from the first base surface in an angled
manner, is preferred. The bottom of the sealing cap is
thus of plate-like design. This has the advantage of it
being possible for droplets of the cleaning liquid
which collect on the surface of the sealing cap
following the cleaning operation to run together, as a
result of gravitational force, to the first base
surface of the sealing cap and thus to be removed more
easily in the case of a possible drying operation.
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It is additionally preferred if the bottom is
designed as the lateral surface of a truncated cone.
The bottom of .the sealing cap thus extends in a wedge-
like manner into the mouth region of the container. The
wedge shape also helps droplets of the cleaning liquid
run together.
Finally, an exemplary embodiment of a closure
which is distinguished in that the metal of the closure
cap- is aluminium and the sealing cap consists of
plastic is preferred. Furthermore, the sealing cap may
consist of a metal, preferably aluminium, coated with a
sealing compound. The selection of these materials
guarantees straightforward and also inexpensive
production of the closure cap and of the sealing cap.
The invention is explained in more detail
hereinbelow with reference to a drawing, in which:.
Figure l shows the mouth region of the container
during the operation of fitting the sealing
cap, in section;
Figure 2 shows the mouth region during the operation
of cleaning the latter by means of a cleaning
liquid, in section;
Figure 3. shows the mouth region during the operation
of fitting the closure cap, in section; and
Figure 4 shows the mouth region following the
operation of screwing on the closure cap, in
section.
Figure 1 shows the mouth region 1 of a
container 2. The mouth region 1 has an external thread
3 and a peripheral bead 5 arranged therebeneath. A
sealing cap 7 comprising a searing insert is fitted
onto the mouth region 1 of the container 2, as is
indicated by arrows 9. The sealing cap 7 has a bottom
11, a peripheral wall 13 which extends from the bottom
11, and a flange 15 which adjoins the wall 13. The
flange 15 is provided with a bent-down border 17. The
bottom 11 of the sealing cap 7 is made up of a first
base surface 19 and of a second base surface 21, which
extends from the first base surface in an angled
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manner. The sealing cap 7 also has, at the bottom end
of the peripheral wall 13, a retaining means 25, which ,
is designed in this case as a peripheral web 23.
The retaining means may also be realized by a
press fit, that is to say in that the sealing cap 7 is
retained securely solely by virtue of its dimensions
being coordinated with the mouth region 1. In this
case, it is also possible for the web 23 to be
dispensed with.
It is also possible for the bottom 11 of the
sealing cap 7 to be designed in the form of the lateral
surface of a cone or truncated cone. As seen in cross
section, it then extends approximately in a wedge
shaped manner into the mouth region 1 of the
container 2.
The first base surface 19 of the bottom 11 of
that exemplary embodiment of the sealing cap 7 which is
illustrated here has, for e.xainple, a thickness of
approximately 0.5 mm. The thickness of the second base
surface 21 of the bottom 11 is approximately 0.4 mm. In
the region of the peripheral wall 13, the thickness of
the sealing cap 7 is approximately 0:3 mm. In the
region where it does not have a bent-down border 17,
the flange 15 has a thickness of 0.4 mm, while the
thickness is approximately 0.7 mm in the region of the
border 17. The peripheral wall 13 and the second base
surface 2.1 of the bottom 11 enclose an angle (3 of
approximately 110°. The angle a between the first base
surface l9 and the second base surface 2l of the bottom
11 is approximately 160°.
The exemplary embodiment of the sealing cap 7
of Figure l clearly shows which surfaces of the sealing
cap 7, apart from the peripheral web 23, interact with
the mouth region l of the container 2. Thus, with the
sealing cap 7 introduced into the mouth region l of the
container 2 to the full extent, the bent-down border 17
of the flange 15 interacts with an outer surface 27 of
the mouth region 1, while the horizontal section of the
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flange 15 interacts with a top side 29 of the mouth
region 1.
The top border of the sealing cap 7 illustrated
in Figure 1 is illustrated differently on the right-
s hand side and left-hand side. On the right-hand side,
it is possible to see that exemplary embodiment of the
sealing cap 7 which has been described up until now. A
further embodiment is represented on the left-hand side
of the sealing cap 7. This further embodiment is
distinguished in that the flange 15 merges into a
dawnwardly angled wall region 30a which forms something
of a peripheral ring which is of more or less
cylindrical design. Said wall region engages over the
outside of the mouth region 1 of the container 2 when
the sealing cap 7 has been fitted onto the container 2.
This results, on the one hand, in the sealing cap 7
being retained firmly on the container and, on the
other hand, in an additional sealing surface.
It should also be pointed out.here that it is
possible for the peripheral flange 15 of the sealing
cap also to be designed without a bent-down border 17
and without the downwardly angled wall region 30a, that
is to say for it to be designed such that it runs
horizontally to the outermost border. It is possible
here, in turn, to distinguish between two cases: in the
case of a first variant, the flange 15 always remains
in the rectilinearly rwnning, horizontal form, that is
to say even when the container 2 is later definitively
closed by a closure cap,' this being discussed in more
detail hereinbelow. In the case of a second variant, it
is possible, during the operation of fitting the
closure cap, for the outermost border region of the
flange 15 to be formed onto the outside of the
peripheral container wall. Depending on the inner
design of the closure cap, it is possible for the bent-
down border 17 or e=Lse the downwardly angled wall
region 30a to be formed here.
It is thus possible for the initially
horizontally peripheral flange 15, during the
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definitive closure operation, to be shaped, that is to
say possibly deep-drawn, in order-to form the bent-down
border 17 or, in particular, the angled wall region 30a
or the peripheral ring.
It can also be seen in Figure 1 that it is
possible to provide on the side which is directed away
from the interior of the container 2, that is to say on
the top side of the sealing cap 7, webs 30b which run
from the peripheral wall 13 to the centre line M, which
is depicted by dashed lines. The. webs, the number of
which can be selected freely within wide limits, all
converge in the region of the centre line. The width
thereof can be selected essentially freely. It is
possible for the height of the web 30b to remain
essentially the same over the length thereof. In the
case of the exemplary embodiment illustrated here;
provision is made for the height of the web 30b to
decrease in the direction of the centre line M starting
from the peripheral wall 13.
The arrangement of the webs 30b may be selected
such that in each case two mutually opposite webs are
located on an imaginary diameter line of the sealing
cap 7. Provision is made here for them to follow an
imaginary radius line. For example, six such. webs,
which- are spaced apart from one another at equal
distances, are provided.
On the one hand, the webs 30b serve for
stiffening the sealing cap 7. On the other hand,
however, it is also possible to provide for the sealing
cap 7 to be produced from an oxygen-absorbing material,
in order to absorb the oxygen present between the
closure and contents of the container 2 following the
operation of closing the same. This makes it possible
to achieve a situation where the contents of the
container, for example beer, have/has a better shelf-
life. In this case, rather than just serving for
stabilizing the sealing cap 7, the webs also serve for
introducing additional material into the closure cap,
in order to ensure a higher level of oxygen absorption.
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Moreover, the oxygen-absorbing surface of the sealing
cap 7 is elevated by the webs.
The webs 30b described here may be provided
both in the case of a sealing cap 7 which is of the
embodiment illustrated on the right-hand side in
Figure 1 and in the case of sealing caps iahich are of
the embodiment represented on the side illustrated on
the left of the figure.
Figure 2 illustrates the sealing cap 7, which
has been introduced into the mouth region 1 of the
container 2 to the full extent, during the cleaning
operation. The same parts are provided with the same
designations as in Figure 1, so you are referred to the
relevant description in this respect.
During the operation of fitting the sealing cap
7 onto the mouth region of the container, foam produced
during the filling operation or foam formed by the
injection of hot water/steam is expelled and the
contents are closed off in an air-tight manner. Oxygen
is expelled from the interior of the container by way
of the foam moving out of the container mouth 1. This
is a very desirable effect in particular in the case of
the operation of filling beer, because residues of
oxygen in the interior of the container 2 adversely
effect the shelf-life of the contents or of the bee r.
Following the operation of fitting the sealing
cap 7, which thus serves as a shaped seal or also as a
preliminary closure, and is also referred to in
specialist circles as a displaces, the interior of the
container is protected against the penetration of
oxygen.
Since the sealing cap 7 only closes the
uppermost mouth region 1 of the container 2, the
container wall is unobstructed and thus easily
accessible for a cleaning operation. Contents residues,
in particular sugar, may thus be removed easily and
virtually without leaving anything behind, with the
result that bacteria and, in particular, mould cannot
find a breeding ground.
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Figure 2 shows a cleaning tool 33 comprising a
flushing nozzle 31. The flushing nozzle 31 discharges a
cleaning liquid 35 in the form of a jet onto the mouth
region 1 of the container 2. It is thus possible for
residues of the contents of the container 2 which are
located in the mouth region 1 of the container 2, in
particular in the region of the external thread 3 and
of the peripheral bead 5, to be removed by the cleaning
liquid 35 without droplets of the cleaning liquid 35
being able to pass into the interior of the
container 2. The cleaning liquid 35 may be water alone
or also water with an addition of detergent or
disinfectant.
Instead of carrying out the cleaning operation
with a cleaning liquid 35, the mouth region of the
container may be brushed off by means of a brush (not
illustrated) or wiped off by means of a wiping means
(not illustrated either). Of course, it is also
possible for the methods of cleaning cited to be
combined with one another.
Figure 2 shows a flushing nozzle 31 by means of
which, by way of example, the. mouth region 1 which is
to be cleaned is sprayed with a cleaning liquid from
above. It is also conceivable to provide a flushing
nozzle which sprays the container with cleaning liquid
from the side, in particular. in the top region in the
vicinity of the sealing cap 7. Adhering contents, in
particular sugar and the like, can be removed
particularly effectively using this flushing direction.
At the same time, it is possible for a special blowing
head to be lowered onto the sealing cap from above,
said blowing head blowing out, or flushing out with
liquid, contamination which is present on the top- side
of the sealing cap. In this case, the blowing head
presses the sealing cap 7 onto the mouth region l, with
the result that, even in the case of a very strong
flushing jet, the situation where the sealing cap is
accidentally lifted off is reliably avoided.
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Following the cleaning step, it is possible for
a drying step (not illustrated in the drawing) to take
place, in the case of which a blowing-nozzle-containing
drying tool blows a drying gas onto the mouth region of
the container 2, as a result of which the droplets of
cleaning liquid 35 which are still adhering to the
mouth region 1 of the container 2 or to the sealing
cap 7 are removed from the mouth region 1. An example
of the possible drying gas is air. The drying operation
may also take place in some other suitable manner, for
example by means of heat radiation and/or a drying
agent.
The cleaning action of the cleaning liquid 35
and the drying action of the drying gas may be enhanced
by the cleaning liquid and the drying gas being heated
before being applied to the mouth region 1.
Figure 2 also clearly shows how the sealing
insert 7 is supported with clamping action by the
retaining means 25, in this case by the web 23, in the
mouth region 1 of the container _2. This clamping action
can be further enhanced, in the case of a somewhat
longer peripheral web 23, by a compression extending
over the entire thickness of said web.
Not illustrated in the drawing is an exemplary
embodiment of the sealing cap 7 in the case of which
the bottom of the sealing cap, rathe r than being
located in the mouth region 1 of the container 2,
extends essentially above said region. In the case of
this exemplary embodiment, the peripheral web is
arranged such that it subjects the outside of the mouth
region 1 to a clamping action. In this case too, it is
possible for the web to be replaced by a press fit
between the sealing cap and outside. Of course, it is
posBible for sealing caps to be designed such that webs
are provided on the inside and on the outside, a press
fit is provided on the inside and on the outside, or
that a web is provided on one side - on the inside or
outside - and a press fit is provided on the other side
- on the outside or inside.
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Figure 3 shows the mouth region 1 of the
container 2 with the sealing cap 7 located therein, and
serving as a sealing insert, during the operation of
fitting a screw cap 37, which is illustrated
symbolically by arrows 39. The same parts are provided
with the same designations as in Figures 1 and 2, so
you can refer once again to the relevant description in
this respect. Not yet present in Figure 3 is a
retaining means, or internal thread 41, which is
located in the interior of the closure cap 37 and,
following the operation of closing the container, is in
engagement with the external thread 3 of the mouth
region 1. In contrast, Figure 3 clearly shows a tamper-
proof band 43 which, following the closure operation,
is adapted in shape to the peripheral bead 5 of the
mouth region 1:
Figure 4 shows the mouth region l of the
container 2 with the sealing cap 7 and the closure cap
37 once the container 2 has been closed by the closure
cap ,37. Once again, the same parts are provided with
the same designations as in Figures 1 to 3, so you are
referred to the relevant description.
It is clearly shown how, with the container 2
closed, the external thread 3 of the mouth region 1
interacts with the internal thread 41 of the closure
cap 37; which is designed in this case as a screw cap,
and the peripheral bead 5 of the mouth region 1
interacts with the tamper-proof band 43 of the closure
cap 37.
Also clearly visible in Figure 4 is a latching
means 47 which is designed as a protrusion 45 running
round at least in certain areas. Running round in
certain areas here means that the protrusion may be
made up of a multiplicity of individual lug-like
protrusions. The latching means 47 serves for producing
a form-fitting or force-fitting connection between the
sealing cap 7 and the closure cap 37 during the
operation of closing the container 2. If the container
2 is opened by a consumer, that is to say if the
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closure cap 37, which is designed as a screw cap, is
unscrewed from the mouth region 1 of the container 2,
then the latching means 4? of the closure cap 37 is
connected to the border 17 of the sealing cap 7 such
that it is carried along. The force applied to the
screw cap 37 by the consumer is thus transmitted to the
sealing cap 7 via the latching means 47 and the border
17 of the flange 15. Since this force in each case is
greater than that force by means of which the
encircling web 23 is supported in the mouth region 1 of
the container 2, it is ensured that the sealing cap 7
is removed from the mouth region 1 of the container 2
preferably always together with the closure cap 37. If
the consumer closes the container 2 again, then the
closure cap 37 and the sealing cap 7 are fitted or
screwed onto the mouth region 1 of the container 2
together. The sealing action of the sealing cap 7 is
maintained even after the container 2 has been opened
and closed a number of times.
Depending on whether the closure cap consists
of metal or plastic, that state of the container 2
which is illustrated in Figure 4 is produced. in two
different ways: In the case of a closure cap made of
metal, a cap blank is fitted onto the mouth region 1 of
,the container 2, which still does not have any internal
thread 4l. The latter is. produced for the first time by
the cap blank being worked by means of a shaping tool:
first of all, however, the transition region. between
the lateral surface of the cap blank and the bottom
which closes the mouth of the container 2 is usually
deep-drawn, in order for the sealing insert or the
sealing cap to be pressed with sealing action against
the container. The lateral surface is then pressed, by
means of a suitable pressure-exerting roll, agains the
mouth region 1, in particular against the external
thread 3 thereof, as a result of which the internal
thread 41 is formed. In contrast, in the case of a
closure cap consisting of plastic, rather than a blank,
the already formed closure cap is fitted. The plastic
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closure cap thus already comprises the internal thread,
with the result that all that is required for the
operation of closing the container is to screw on the
closure cap.
In order to simplify matters, with the
exception of the cleaning tool 33 in Figure 2, the
drawing does not illustrate any of the tools which
carry out the individual steps of the closing process,
that is to say the fitting tools, the drying tool, the
shaping tool and the screwing-on tool. The second
fitting tool which is used in practice here is a
closing head or magnetic closing head having a
conventional cap shoe.
The above description is based on the closure
being of two-part design and having a closure cap and a
sealing cap.. It is thus a decisive factor that the
closure is in two parts, this making it possible for a
container to be closed provisionally by means of the
sealing cap following the filling operation in order
that a cleaning operation can be carried out without
contents of the container being adversely affected.
This results in it being possible for contents residues
to be removed .from the mouth region of the containe r
and for the attack by bacteria and the like thus to be
reduced or avoided altogether. Following the cleaning
operation, the container is then closed off
definitively by means of the closure cap.
Up until now, it has been assumed that the
closure cap is designed as a closure-cap blank which is
then shaped into a. screw closure in a shaping
operation. It is also possible for a finished screw
closure, in particular made of plastic, to be fitted or
screwed onto a container closed by a sealing cap.
It should also be pointed out here expressly,
however, that the closure cap may also be designed as a
crown cap which, following the provisional closure of
the container and a cleaning operation, is fitted or
pressed onto the container and/or the sealing cap and
is formed onto the mouth region of the container, and
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is thus retained securely, if appropriate using a
suitable shaping tool.
Use may be made here not just of conventional
crown caps but also so-called rotary crown caps which,
following the conventional closing and forming-on
operations, can be unscrewed from the container or the
mouth region thereof. In the latter case, the outside
of the container, of course, has to be provided with a
thread or with a groove formation acting as a thread.
The types of closure cap cited here are only
given by way of example. It is, of course, also
conceivable for the sealing cap 7, which acts as a
preliminary closure or shaped seal, to be combined with
differently designed closure caps, for example also
with so-called twist-off closure caps. The essential
factor is that, overall, the closure is designed with
at least two parts and the sealing cap or the
preliminary closure closes the container first of all
in an air-tight manner and the closure cap then closes
off the container definitively, it then being possible
for the specific configuration of the closure cap to be
selected freely in this context.
The sealing cap 7 may then be adapted in
configuration to the different types of closure cap. In
the case of rotary crown caps, for example, it is
conceivable for the sealing cap, as has been explained
with reference to Figure l, to be formed onto the outer
wall region of the container 2 by the closure cap and
thus to extend over a relatively large region of the
outer wall, as has been explained, for example, with
reference to the downwardly angled wall region 30a. In
this case, the sealing cap may be provided with a
thread, which then engages with an external thread of
the container. Moreover, it is also possible merely to
provide thread turns on the outer wall of the container
and to press the sealing cap against these, during the
closure operation, such that, in the region of the
contact with the thread turns on the container,
CA 02384279 2002-03-07
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corresponding thread turns are then made in the plastic
of the sealing cap.
It is the common feature of all the types of
closure that, following completion of the closing
operation, the initially two-part closure may
preferably be handled as a unit, that is to say,
following the operation of fitting the closure cap, the
sealing cap latches into the interior of said closure
cap because, as has been described, for example, with
reference to Figure 4, latching means 47 are provided
th-ere and these, following operation of fitting the
closure cap, retain the sealing cap securely. In the
case of all the types of closure described here, it is
thus possible, on account of the closure being in two
parts, for a cleaning operation to be carried out,
following the filling operation and the provisional
closure of the container by means of the sealing cap,
and then for the container to be closed definitively
for the first time by means of the closure cap, which,
as has been said, may be of any desired design.
Duringl the operation of fitting the closure
cap, the, outer border of the sealing cap is pressed
against the wall of the container, and forms thereon,
with the result that the container is closed off in a
pressure-tight manner. This applies to both embodiments
of the sealing cap which has been explained with
reference to Figure 1 and. to all the variants of the
closure cap which have been described here.
The sealing cap preferably consists of plastic,
combined forms, in which the sealing cap may consist of
a metal base coated with plastic, also being possible.
The sealing cap may also be made up of more than two
materials. Ln particular in the case of all-plastic
sealing caps, the plastic achieves the situation where,
in the case of screw closures, the opening forces are
reduced to a reasonable level on account of the sliding
capacity of plastic, that is to say the opening forces
can be adjusted relatively well to small values on
account of the sliding capacity, with the result that
CA 02384279 2002-03-07
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no problems arise when the container is opened by the
consumer. Moreover, in the case of the selection of the
material of the sealing cap, it is also possible to use
oxygen-absorbing plastic or a barrier material, with
the result that the shelf-life of the contents present
in the container is increased.
By virtue of a suitable selection of the
plastic for the sealing cap, it is possible to ensure
that the sealing action of- the closure remains
essentially constant even when the container is opened
arid closed a number of times, with the result that it
is also possible to achieve a high level of
reliability. On the one hand, the container can be
closed to good effect in order to avoid the contents
perishing and, on the other hand, by virtue of the
specific design of the sealing cap and of the closure
cap, excess-pressure limitation can be ensured, and
maintained, even when the closure is opened and closed
a number of times.
Finally, all that remains to point out is that
the process described and the closure cap illustrated
can be . used for both disposable and reusabl a
containers. If the container 2 is sent back to the
manufacturer together with the screw cap and the
sealing insert located therein, then the manufacturer
can even separate the closure cap :and the sealing
insert or the sealing cap from one another again by
using suitable tools. In particular, it is readily
possible for these two parts to be fed separately to a
recycling process.
When the closure described is used, the process
described allows hygienically satisfactory closure of a
container. This is possible in that the closure
comprises a closure cap and a sealing insert which is
formed separately and can be handled separately, the
mouth region of the container being cleaned between the
operations of fitting the sealing insert and fitting
the closure cap.