U.S. patent application number 12/778184 was filed with the patent office on 2010-11-18 for packaging machine and method for closing containers with lids.
This patent application is currently assigned to MULTIVAC SEPP HAGGENMULLER GMBH & CO. KG. Invention is credited to Hans-Joachim Boekstegers, Elmar Ehrmann, Helmut Sparakowski.
Application Number | 20100287893 12/778184 |
Document ID | / |
Family ID | 42456611 |
Filed Date | 2010-11-18 |
United States Patent
Application |
20100287893 |
Kind Code |
A1 |
Ehrmann; Elmar ; et
al. |
November 18, 2010 |
PACKAGING MACHINE AND METHOD FOR CLOSING CONTAINERS WITH LIDS
Abstract
The invention relates to a method for closing already preformed
and separated containers (19), for example trays, with a lid foil
(24) in a closing station (3). The invention is characterized in
that a deep-drawable foil is used as lid foil (24), that the lid
foil (24) is deep-drawn in a forming means (23) of the packaging
machine (1), and that the deep-drawing of the lid foil (24) is
accomplished before the containers (19) are closed with the lid
foil (24). The invention also relates to a packaging machine (1)
suited for carrying out such a method.
Inventors: |
Ehrmann; Elmar; (Bad
Groenenbach, DE) ; Sparakowski; Helmut; (Tannheim,
DE) ; Boekstegers; Hans-Joachim; (Starnberg,
DE) |
Correspondence
Address: |
BROOKS KUSHMAN P.C.
1000 TOWN CENTER, TWENTY-SECOND FLOOR
SOUTHFIELD
MI
48075
US
|
Assignee: |
MULTIVAC SEPP HAGGENMULLER GMBH
& CO. KG
Wolfertschwenden
DE
|
Family ID: |
42456611 |
Appl. No.: |
12/778184 |
Filed: |
May 12, 2010 |
Current U.S.
Class: |
53/487 ;
53/296 |
Current CPC
Class: |
B65B 7/164 20130101;
B65B 7/01 20130101; B65B 47/02 20130101; B65B 47/10 20130101 |
Class at
Publication: |
53/487 ;
53/296 |
International
Class: |
B65B 7/28 20060101
B65B007/28; B65B 17/00 20060101 B65B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 13, 2009 |
DE |
102009020892.5 |
Claims
1. A method for closing already preformed and separated containers
with a lid foil in a closing station of a packaging machine, the
method comprising: deep-drawing the lid foil with a forming device
of the packaging machine; and closing the containers with the lid
foil in the closing station; wherein for each container, the
deep-drawing is performed prior to the closing.
2. The method according to claim 1 further comprising heating the
lid foil upstream of the forming device and/or in the forming
device.
3. The method according to claim 1 wherein the deep-drawing is
performed such that the lid foil is deep-drawn at least in sections
towards a side of the lid foil facing the containers during the
closing.
4. The method according to claim 1 wherein the deep-drawing is
performed such that the lid foil is deep-drawn at least in sections
towards a side of the lid foil facing away from the containers
during the closing.
5. The method according to claim 1 wherein for each container the
deep-drawing is performed such that at least one concave and/or one
convex section is formed on a side of the lid foil facing the
container during the closing.
6. The method according to claim 1 wherein the deep-drawing is
carried out in the closing station.
7. The method according to claim 1 wherein the lid foil comprises a
flexible foil or a hard foil.
8. The method according to claim 1 wherein the lid foil comprises a
multilayer foil.
9. The method according to claim 1 wherein for each container the
closing comprises placing the lid foil onto the container by a form
fit.
10. The method according to claim 1 wherein for each container the
closing comprises sealing the lid foil onto the container.
11. The method according to claim 10 wherein, after sealing the lid
foil onto the containers, the lid foil is moved along by movement
of the closed containers.
12. A packaging machine for closing already preformed and separated
containers with a lid foil, the packaging machine comprising: a
forming device configured to deep draw the lid foil to form lid
sections; and a closing station for closing the containers with the
lid sections; wherein the packaging machine is operated such that,
for each container, a lid section is formed prior to closing the
container with the lid section.
13. The packaging machine according to claim 12 wherein, for each
container, the forming device is configured to form at least one
concave and/or one convex section on a side of the lid foil facing
the container during the closing of the container at the closing
station.
14. The packaging machine according to claim 12 wherein the forming
device comprises an exchangeable insert for deforming the lid
foil.
15. The packaging machine according to claim 12 further comprising
a conveyor device for conveying the lid foil, and a transport
device for transporting the containers.
16. The packaging machine according to claim 15 wherein the
conveyor device comprises a clamp chain.
17. The packaging machine according to claim 12 wherein the closing
station comprises a tool for placing and/or sealing the lid foil
onto the containers.
18. The packaging machine according to claim 17 wherein the tool
comprises a lower tool and an upper tool, wherein at least one of
the lower tool and the upper tool is movable with respect to the
other of the lower tool and the upper tool.
19. The packaging machine according to claim 18 wherein the lower
tool and the upper tool are configured to be spaced apart by the
relative movement at least far enough to correspond to the sum of a
height of a container and a height of a lid section of the lid
foil.
20. The packaging machine according to claim 12 wherein the forming
device is located at the closing station.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims foreign priority benefits under 35
U.S.C. .sctn.119(a)-(d) to German patent application number DE
102009020892.5, filed May 13, 2009, which is hereby incorporated by
reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a method for closing
containers, as well as to a packaging machine for carrying out such
a method.
BACKGROUND
[0003] Packaging machines for closing already preformed and
separated containers are known in the form of so-called tray
sealers, for example from DE 10 2006 018 327 A1. Such machines are
fed with already preformed and separated trays which are usually
stacked and stocked after they have been formed. The containers are
individually removed from the stock and placed onto a conveying
belt where they are filled with a product from above. In the
conventional tray sealer, a sealing foil is subsequently applied
onto the trays that are open to the top which closes as well as
seals the trays.
[0004] In conventional tray sealers, the sealing foil must not be
stretched by the product, as otherwise the sealing foil might tear
off. Consequently, the trays must be comparably deep to prevent the
products from projecting over the edge of the trays. This excessive
height of the trays, however, also involves drawbacks. On the one
hand, this leads to an increase in the required amount of material
and costs of a package. On the other hand, less preformed or filled
trays can be accommodated per volume, so that costs increase for
the stock-keeping of the empty trays as well as for the
distribution of the filled and closed trays.
SUMMARY
[0005] It is an object of the present disclosure to overcome these
drawbacks with structural means that are as simple as possible.
[0006] An embodiment of the present disclosure involves using a
deep-drawable foil for closing already preformed and separated
containers, and the foil is deep-drawn in a forming means or device
of a packaging machine before the containers are closed with the
lid foil. This deep-drawing offers the advantage that the package
can be much better adapted to the respective product than before,
although the containers are already preformed. In particular,
products projecting over the container edge can also be
accommodated in the containers, without the lid foil stretching
over the product. Moreover, there are also esthetic advantages as,
in contrast to conventional tray sealers, the upper side of each
package does no longer have to be flat, but can be structured.
[0007] The lid foil may be heated upstream of and/or in the forming
device to permit deep-drawing. The preheating of the lid foil
upstream of the forming device can accelerate deep-drawing and
reduce superfluous waiting times of other components of the
packaging machine.
[0008] It is conceivable to deep-draw the lid foil towards the side
of the lid foil facing the container during closing altogether or
at least in sections. In this manner, a lid section which projects
into the interior of the container is formed in the lid foil. This
is in particular suited for products or regions of a product which
are situated at a lower level than the edge of the container.
[0009] As an alternative or in addition, it is conceivable to
deep-draw the lid foil towards the side of the lid foil facing away
from the container during closing altogether or at least in
sections. In this manner, a dome shaped lid section is formed which
projects upwards over the container edge and permits the
accommodation of projecting products without the lid foil
stretching over the product.
[0010] By the method according to the present disclosure, in the
deep-drawing process, at least one concave and/or one convex
section can be formed on the side of the lid foil facing the
container during closing. They can facilitate the placement of
complementary formed regions of the products against the lid to
prevent, for example, shifting of the products in the
containers.
[0011] The forming device can be provided separately from the
closing station. The complete packaging machine, however, becomes
more compact and the method thereby less complex, if deep-drawing
is carried out within the closing station itself.
[0012] As lid foil, a flexible foil or a hard foil could be used,
if they can be deep-drawn in a suited manner.
[0013] Depending on the product, it can be advantageous to use a
multilayer foil as lid foil. For example, a combination of an outer
layer impermeable to oxygen and an inner layer permeable to oxygen
would be conceivable to permit oxygen to flow around the
products.
[0014] In one variant of the invention, the lid foil or the lid
section formed in it, respectively, is only placed onto the
respective containers by a form fit in the form of a "slip lid".
The lid section can, for example, snap in at an edge of the
container to securely connect the lid to the container.
[0015] In addition or as an alternative, it is possible for the lid
foil to be sealed onto the containers, in particular if the
interior of the container is to be hermetically sealed.
[0016] If the lid foil is sealed to the containers, the transport
of the closed containers connected with the lid foil out of the
closing station can cause further lid foil to be drawn behind,
which is used for closing following containers. In this manner, one
could do without a separate conveyor device for the lid foil.
[0017] The present disclosure also relates to a packaging machine
for carrying out a method according to the present disclosure. The
packaging machine comprises a forming means or device for
deep-drawing the deep-drawable lid foil.
[0018] It is appropriate for the forming device to comprise an
exchangeable insert which determines the deformation of the lid
foil to a lid section. This insert can be replaced if it is worn
down, or if a different shape of the lids for the containers is to
be produced.
[0019] Mainly in comparably thick hard foils, the pulling force
acting on the lid foil only by the movement of the closed
containers still connected to the lid foil might not be sufficient.
In this case, it is advantageous to provide, in addition to a
transport means for the containers, such as a conveyor belt or any
other suitable transport device, a separate conveying means for the
lid foil, for example a clamp chain arranged on both sides which
can also be used to stretch the lid foil laterally, or any other
suitable conveyor device.
[0020] The packaging machine according to the present disclosure
may have a tool for placing and/or sealing the lid foil onto the
containers. In this tool, the actual closing of the containers is
thus accomplished.
[0021] The tool itself can comprise a lower tool and an upper tool
which can be moved relative to each other. For example, they can
open for receiving the unclosed containers and reduce the space
between them for closing and possibly evacuating and/or gassing the
containers.
[0022] It is appropriate if the lower tool and the upper tool can
be spaced apart by the relative movement at least far enough to
correspond to the sum of the height of a container and the height
of a lid section of the lid foil. In this manner, the closing tool
also permits the accommodation of containers in which the product
and the lid project over the edge of the container.
[0023] In the following, two advantageous embodiments of the
present disclosure are illustrated more in detail with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective view of a packaging machine
according to the present disclosure;
[0025] FIGS. 2 to 8 show schematic vertical sections through a
first embodiment of the packaging machine in different steps of a
method according to the present disclosure; and
[0026] FIGS. 9 to 15 show a second embodiment of the packaging
machine in different steps of the method according to the present
disclosure.
DETAILED DESCRIPTION
[0027] In the Figures, equal and similar components are provided
with the same reference numerals.
[0028] FIG. 1 shows a first embodiment of a packaging machine 1
according to the invention in a perspective view. This embodiment
is a tray sealer. The packaging machine 1 has a machine frame 2 on
which a closing station 3 is arranged for closing as well as
possibly evacuating, gassing and/or sealing supplied, tray-shaped
containers as well as for cutting a lid foil used for closing. The
closing station 3 is located under a cover 4 that can be
opened.
[0029] The packaging machine 1 furthermore has a feed belt 5 for
feeding the containers, a discharge belt 6 for carrying away the
closed containers, a foil feed roller 7 for taking up and feeding a
roll of a lid foil, a foil stretching means 8 for stretching the
lid foil, as well as a foil residue winder 9 for winding up the
foil residues that remain after sealing. A display 10 permits the
operator of the packaging machine 1 to check and control the
operation of the packaging machine 1. To this end, operational
controls 11 can be provided at the display 10, for example operator
panels or switches to influence the operation of the packaging
machine 1.
[0030] FIG. 2 shows, in a first embodiment of the packaging machine
1 according to the invention, a vertical section through the
closing station 3 in a schematic view. The closing station 3 has a
tool 12 which in turn comprises an upper tool 13 and a lower tool
14. The upper tool 13 and the lower tool 14 can be moved in the
vertical direction relative to each other. The upper and lower
tools 13, 14 can form a closed chamber 15 between themselves in a
closed state (see FIG. 3).
[0031] A lifting table 16 is provided at the lower tool 14 which
can be traveled in the vertical direction via a lifting rod 17
independent of the lower tool 14. The lifting table 16 forms a
recess or cavity 18 for receiving a prefabricated, tray-shaped
container 19. This container 19 can consist, for example, of hard
plastics. After preforming, a plurality of containers 19 are
stacked and stocked in this manner. They can be individually
removed from this stock and placed onto the feed belt 5 of the
packaging machine 1 to be filled there.
[0032] One can see in FIG. 2 that an edge 20 of the container rests
on an edge of the lifting table 16 or cavity 18. One can also see
that the container 19 is filled with a product 21 which projects
upwards beyond the level formed by the edge 20 of the container
19.
[0033] In the present embodiment, the upper tool 13 has a more
complex design. It has on its part three tool components which can
be traveled relatively to each other in the vertical direction
within the upper tool 13 independent of each other as well as
independent of the outer wall 22 of the upper tool 13. The
innermost tool component is a forming means 23 for forming a lid
section in the single- or multilayer lid foil 24 advance by the
foil feed roller 7. In the present embodiment, the forming means 23
may comprise any suitable forming device, such as a forming mold or
tool having a concave design on a surface 25 facing the container
19. The forming means 23 can have vacuum lines (not shown) to
create a vacuum between the surface 25 and the lid foil 24.
[0034] Above the forming means 23, a sealing plate 26 is arranged
which has sealing edges 27 projecting downwards. The sealing edges
27 are shaped such that they can contact the edge 20 of the
container 19 when the sealing plate 26 is lowered.
[0035] A cutting means 28 is provided above the sealing plate 26,
between the sealing plate 26 and the outer wall 22 of the upper
tool 13. The cutting means 28 may comprise any suitable cutting
device, such as a movable cutting tool having cutting edges 29
projecting downwards which are configured for cutting the lid foil
24 in two. The tool 12 can moreover have means for evacuating
and/or gassing the chamber 15 formed between the upper and the
lower tool 13, 14. For example, the tool 12 may be connected to a
vacuum pump, or any other suitable evacuating device, and/or a gas
supply system.
[0036] The deep-drawable (e.g., thermoplastic) lid foil 24 passes
over a first deflection roller 30 and is there deflected such that
it traverses the interior of the tool 12 essentially in parallel to
the level formed by the edge 20 of the container 19. The residual
sections of the lid foil 24 remaining after the containers 19 have
been closed and the lid sections punched out pass over a second
deflection roller 31 to a residual foil winder 9 to be accumulated
there. Between the foil feed roller 7 and the tool 12, a foil
stretching means 8, which is not represented in FIG. 2 for a better
overview, can be moreover provided. The foil stretching means 8 may
be any suitable device, such as a movable plate or a system of
rotatable drums or cylinders that includes one or more cylinders
that are movable toward and away from another cylinder.
[0037] Between the foil feed roller 7 and the first deflection
roller 30, a heating means or a preheating means 32 (if a further
heating step is performed), respectively, is moreover provided. The
heating means 32 can be a heating plate which is heated, for
example, via a thermal fluid or an electric heating medium. The
heating means 32 is used to heat a given section 33 of the lid foil
24 to a temperature which permits thermoplastic forming of the lid
foil 24 during a deep-drawing operation.
[0038] With reference to FIGS. 2 to 8, a method according to the
present disclosure and the operating sequence of the packaging
machine 1, respectively, will now be illustrated.
[0039] FIG. 2 shows the tool 12 of the packaging machine 1 in a
state in which a tray 19 filled with a product 21 has been inserted
into the cavity 18 of the lifting table 16 and guided into the
interior of the tool 12. For this purpose, the upper and the lower
tools 13, 14 can be removed from each other to such an extent that
the distance A between the lower edge of the upper tool 13 and the
upper edge of the lower tool 14 is larger than the sum of the
height of the container 19 and the projecting part of the product
21, to permit in this manner the introduction of the filled
container 19 into the tool 12. A certain section 33 of the lid foil
24 is heated under the heating means 32.
[0040] FIG. 3 shows the tool 12 in a state in which first the lid
foil 24 has been conveyed far enough for the heated section 33 to
be located underneath the forming means 23. At this time, the feed
of the lid foil 24 is stopped. One can see in FIG. 3 that the upper
tool 13 and the lower tool 14 move towards each other until they
clamp the lid foil 24 between their edges and form a closed chamber
15 between themselves. As the feed of the lid foil 24 is stopped,
now a further section 33' of the lid foil can be brought to the
temperature required for forming under or in the heating means
32.
[0041] It could already be seen in FIG. 3 that the forming means 23
contacts the lid foil 24 when the upper tool 13 is lowered. Arrows
34 in FIG. 4 indicate that now a vacuum is created at the surface
25 of the forming means 23 by suited provisions. In connection with
the contact between the forming means 23 and the lid foil 24, this
vacuum takes care that the heated section 33 of the lid foil 24 is
pulled against the concave surface 25 of the forming means 23 and
in this manner deep-drawn to form a lid section 35.
[0042] The lid section 35 is represented in FIG. 5. It has a shape
which is complementary to the edge 20 of the container 19 on the
outer surface. On the side facing the product 21, the lid section
35 is concave.
[0043] FIG. 6 shows the tool 12 in a state in which--starting from
the state in FIG. 5--the lifting table 16 was lifted until the edge
20 of the container 19 came into contact with the lid foil 24. This
movement of the lifting table 16 is indicated by arrow 36.
Simultaneously--as indicated by arrow 37--the sealing plate 26 was
lowered until its sealing edges 27 came into contact with the lid
foil 24 from above. In this state, the lid foil 24 is now sealed
onto the edge 20 of the container 19.
[0044] Subsequently or simultaneously with the sealing, the cutting
means 28 is lowered--as shown in FIG. 7--, so that its cutting
edges 29 cut out the lid foil 24 all around the closed container
19. This movement of the cutting means 28 is indicated by arrow
38.
[0045] In FIG. 8, the tool 12 is opened. This is done by moving the
lower tool 14 and the lifting table 16 downwards and the upper tool
13 with the forming means 23, the sealing plate 26 and the cutting
means 28 upwards. The lid section 35 is firmly connected to the
rest of the container 19 by the sealing and remains at the
container 19. The filled container 19 can now be removed from the
tool 12. At the same time, the lid foil 24 can be transported
forwards, while the rest of the lid foil 24 that remains during
cutting is winding up on the foil residue winder 9. The closing
process can now be performed in the same manner for a subsequent
container.
[0046] FIG. 9 shows a second embodiment of a packaging machine 1
according to the present disclosure. It differs from the first
embodiment in that the forming means 23 for forming the lid
sections is now no longer provided in the closing tool 12, but in
the region of the heating means 32. Apart from that, the upper tool
13 and the lower tool 14 of the closing tool 12 remain unchanged.
In particular, the upper tool 13 still comprises a sealing plate 26
and a cutting means 28, while the lower tool 14 still comprises a
lifting table 16.
[0047] In the second embodiment, the forming means 23 comprises a
first forming half 39 and a second forming half 40. As indicated by
the arrows 41, the two forming halves 39, 40 can be moved relative
to each other perpendicular to the plane of the lid foil 24, so
that they can close around the lid foil 24 or can release the lid
foil 24, respectively.
[0048] In the first forming half 39, an exchangeable inset 42 is
provided. Its surface 43 facing the lid foil 24 defines the shape
of the lid section 35 if the section of the lid foil 24 heated by
the heating means 32 in the opposite second forming half 40 is
pulled closer by applying a vacuum to the surface 43 of the inset
42 to deep-draw the lid foil 24.
[0049] FIGS. 9 to 15 show various steps of the method according to
the present disclosure during the operation of the packaging
machine 1 according to the second embodiment. FIG. 9 shows the
packaging machine 1 in a state in which a fresh section of the lid
foil 24 has been brought into the forming means 23.
[0050] In FIG. 10, the two forming halves 39, 40 of the forming
means 23 have been closed. Arrows 44 indicate that a vacuum is
created at the inset 42 of the forming means to place the lid foil
24 in this region against the inset 42 of the first forming half 39
and to form a lid section 35 in this manner. The inset 42 can be
exchanged if lid sections 35 having a different shape are to be
produced.
[0051] FIG. 11 shows the state of the packaging machine 1 after the
lid foil 24 has been deep-drawn in the forming means 23. The lid
foil 24 now has a lid section 35.
[0052] In FIG. 12, the two forming halves 39, 40 have been removed
from each other. The opening 45 formed between them now must be
large enough--at least in the exiting direction out of the forming
means 23--to let the domed lid section 35 pass.
[0053] Between the state in FIG. 12 and the state in FIG. 13, the
lid foil 24 has been moved into the conveying direction 45 far
enough for the lid section 35 now to be positioned within the
closing tool 12 over the container 19 to be closed. The first
deflection roller 30 here only lies against an outer edge of the
lid foil 24, so that it does not collide with the lid section 35 in
the central region of the lid foil 24.
[0054] FIG. 14 shows the packaging machine 1 in a state in which
the closing tool 12 has been closed by moving the upper tool 13 and
the lower tool 14 towards each other. A contact between the sealing
edges 27 of the sealing plate 26 and the edge 20 of the container
19, that is close by due to the lifting of the lifting table 16,
permits to seal the lid foil 24 to the container 19. Simultaneously
or subsequently, the cutting means 28 has been lowered to cut out
the closed container. The forming means 23 has simultaneously
closed around a new section of the lid foil 24 to form a further
lid section 35.
[0055] In FIG. 15, the forming means 23 as well as the closing tool
12 have been opened. The closed container 19 can now be removed
from the tool 12, and the cycle can start anew.
[0056] Starting from the two embodiments described in detail, a
method according to the present disclosure and a packaging machine
according to the present disclosure can be modified in many ways.
It is, for example, conceivable for the lid sections 35 not to be
sealed to the edge 20 of the container 19, but to only be placed
onto the container 19 by a form fit in the form of slip lids. It is
moreover possible to impart any arbitrary shape to the lid section
35. In the first embodiment, too, the forming means 23 can have an
exchangeable inset 42. Though it is not shown, several lid sections
35 can be manufactured one after or one next to the other in the
forming means 23, and several containers 19 can be simultaneously
closed in the closing station 3.
[0057] While exemplary embodiments of the invention have been
illustrated and described, it is not intended that these
embodiments illustrate and describe all possible forms of the
invention. Rather, the words used in the specification are words of
description rather than limitation, and it is understood that
various changes may be made without departing from the spirit and
scope of the invention. Additionally, the features of various
implementing embodiments may be combined to form further
embodiments of the invention.
* * * * *