U.S. patent application number 11/083018 was filed with the patent office on 2005-10-06 for two-ply blank (cold sealable).
Invention is credited to Nekula, Lambert, Niederer, Andreas, Reiterer, Franz.
Application Number | 20050218143 11/083018 |
Document ID | / |
Family ID | 34831642 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050218143 |
Kind Code |
A1 |
Niederer, Andreas ; et
al. |
October 6, 2005 |
Two-ply blank (cold sealable)
Abstract
An element (1) punched out in a cover shape, for sealing of
containers (7), includes a first ply (2) and a second inner ply (3)
which is provided with a heat-sealable layer (5) on its side facing
the container. The plies (2, 3) are connected to one another over
their surface sides (2', 3'.) facing one another by a cold-sealing
layer (4), the adhesion between the plies (2, 3) being lower than
that between the inner ply (3) and the container edge (8). On the
inner ply (3) there can be scoring (10) which is exposed by peeling
off the outer ply (2). If for example packaged material which is
suited for heating in a microwave oven is stored in the container
(7), the steam which forms during heating can escape through the
scoring (10).
Inventors: |
Niederer, Andreas; (Melk,
AT) ; Nekula, Lambert; (Hofstetten, AT) ;
Reiterer, Franz; (Getzersdorf, AT) |
Correspondence
Address: |
YOUNG & THOMPSON
745 SOUTH 23RD STREET
2ND FLOOR
ARLINGTON
VA
22202
US
|
Family ID: |
34831642 |
Appl. No.: |
11/083018 |
Filed: |
March 18, 2005 |
Current U.S.
Class: |
220/359.2 ;
220/359.3 |
Current CPC
Class: |
B65D 77/206 20130101;
B65D 2577/2091 20130101 |
Class at
Publication: |
220/359.2 ;
220/359.3 |
International
Class: |
B65D 041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2004 |
AT |
A 481/2004 |
Claims
1. Element (1) which is punched out in a cover shape for sealing of
containers (19), consisting of a first outer ply (2) and a second
inner ply (3) which is provided with a heat-sealable layer (5) on
its side facing the container, characterized in that the plies (2,
3) are connected to one another over their surface sides (2', 3')
facing one another by a cold-sealing layer (4), and that the
adhesion between the plies is lower than that between the inner ply
(3) and the container edge (8).
2. Element which is punched out in a cover shape as claimed in
claim 1, wherein the adhesion between the plies (2) and (3) is 0.2
to 4.5 N/15 mm measured according to DIN EN 28510-1.
3. Element which is punched out in a cover shape as claimed in
claim 1, wherein the adhesion between the inner ply (2) and the
container edge (8) is greater than or equal (.gtoreq.) 5 N/15 mm
measured according to DIN EN 28510-1.
4. Element which is punched out in a cover shape as claimed in
claim 1, wherein the plies (2) and (3) are present as monomaterials
and/or compound materials.
5. Element which is punched out in a cover shape as claimed in
claim 1, wherein the outer ply (2) is a metal foil, .preferably an
aluminum foil.
6. Element which is punched out in a cover shape as claimed in
claim 5, wherein the outer ply (2) is provided with an imprint.
7. Element which is punched out in a cover shape as claimed in
claim 6, wherein the imprint has a rough surface.
8. Element which is punched out in a cover shape as claimed in
claim 7, wherein the surface-rough imprint is present in the form
of geometrically arranged spacers.
9. Element which is punched out in a cover shape as claimed in
claim 1, wherein the inner ply (3) consists of plastics.
10. Element which is punched out in a cover shape as claimed in
claim 9, wherein the plastics are selected from the group
polypropylene, polyethylene, polyester, polyacrylate, polyamide, or
polystyrene.
11. Element which is punched out in a cover shape as claimed in
claim 1, wherein the inner ply (3) comprises at least one layer of
paper.
12. Element which is punched out in a cover shape as claimed in
claim 1, wherein the inner ply (3) has scoring (10).
13. Element which is punched out in a cover shape as claimed in
claim 1, wherein the-inner ply (3) has perforations (11).
14. Element which is punched out in a cover shape as claimed in
claim 13, wherein the perforations (11) have the shape of a pour
opening (12).
15. Element which is punched out in a cover shape as claimed in
claim 1, wherein the heat-sealable layer (5) has a rough
surface.
16. Element which is punched out in a cover shape as claimed in
claim 15, wherein the surface roughness is formed by geometrically
arranged spacers (6).
17. Element which is punched out in a cover shape as claimed in
claim 1, wherein the inner ply (3) is formed from a broken lattice
(14) consisting of heat-sealable plastics.
18. Element which is punched out in a cover shape as claimed in
claim 1, wherein in at least one ply (2, 3) there is a
combination-free area in the form of an opening aid, preferably a
pull tab (9, 9').
Description
[0001] This invention relates to an element which is punched out in
a cover shape for sealing of containers, consisting of a first
outer ply and a second inner ply which is provided with a
heat-sealable layer on its side facing the container.
[0002] The use of two-ply covers for sealing of containers in order
for example to enable the flavor protection which is required for
foods is known.
[0003] Furthermore it has been shown that especially in the case of
perishable foods, for the consumer there is an increased demand for
information relating to origin, contents, and storability. In order
to provide enough space for this information, there has been a
transition to printing it on the outer ply of the sealing cover,
conversely the inner ply remains unprinted as much as possible.
This is the case since possible contact of printing inks with foods
is to be avoided.
[0004] To open these packages the upper ply of the cover is pulled
off and only after separating the inner, second ply is access to
the package contents possible.
[0005] But known approaches have the disadvantage that this partial
opening process is often difficult, since sometimes the entire
cover, therefore the two plies, are pulled off the container. But
this is undesirable when flavor protection for the packaged
contents is to continue to be maintained by the second inner ply.
This is necessary for example for larger package contents which can
only be consumed in portions, but also in packages for microwave
dishes.
[0006] Therefore the object of this invention is to devise an
element of the initially mentioned type which is punched out in the
shape of a cover, which preserves the package contents in a
satisfactory manner, especially with respect to flavor protection,
and which can be easily handled in a for the consumer when opening
[sic].
[0007] As claimed in the invention, this object is achieved with an
element which is punched out in a cover shape and which is
characterized in that its plies are connected to one another over
their surface sides facing one another by a cold-sealing layer, and
that the adhesion between the plies is lower than that between the
inner ply and the container edge.
[0008] This varied adhesion makes it possible for the consumer to
easily partially open the container such that in the first opening
step the outer ply is pulled, i.e. peeled, off the inner ply facing
the container. In a second step the inner ply is pulled off the
container edge, an increased force being necessary since the
heat-sealable coating adheres more strongly to the container edge
than the cold-sealing layer between the individual compound
plies.
[0009] Other embodiments of the element which is punched out in a
cover shape as claimed in the invention are disclosed according to
the dependent claims.
[0010] The invention is detailed below using possible embodiments
of the invention. FIG. 1 shows one possible embodiment in which the
ply of the element which is punched out in a cover shape, which ply
faces the container, has an inherently closed surface. According to
FIG. 2 this surface is provided with scoring, as shown in FIG. 3
with perforations for forming a pour opening. As shown in FIG. 4,
the inner ply of the element which is punched out in a cover shape
is made in the form of a lattice.
[0011] In the production of the element 1 which is punched out in a
cover shape as claimed in the invention, for the present the outer
ply 2 or the inner ply 3 is produced.
[0012] For producing the outer ply 2, for example aluminum foil
with a thickness in the range from 10 to 100 microns is used. It is
however also possible to use plastic films in the thickness range
from 10 to 100 microns. The plastics can be selected from the group
polypropylene, polyethylene, polyester, polyacrylate, polyamide, or
polystyrene.
[0013] The outer ply 2 can furthermore be provided with typography
on its surface 'side facing the viewer. It can be both smooth and
also rough in its surface configuration. The surface roughness
yields the desired typography by the irregular, but also regular
arrangement of the print motifs. Furthermore the surface roughness
of the typography facilitates the unstacking of the elements which
are punched out in a cover shape and which are conventionally
stored on top of one another in magazines.
[0014] The aforementioned typography can however also reproduce the
information from which the consumer takes the origin, composition
and storage life of the packaged material.
[0015] After printing the outer ply 2, it is provided with a
cold-sealing layer 4 on its surface side 2'. Cold-sealing
substances are characterized in that by using pressure, but without
additional temperature use, adhesion between two plies can be
produced. The cold-sealing layer can be prepared for example by
applying a polymer-containing emulsion or dispersion. Polymer
emulsions in aqueous form can be for example those with the
commercial name "Crodaseal 22-055" since they meet legal
requirements relating to food. Furthermore it is conceivable to use
a likewise food-compatible, softener-free polymer dispersion based
on acrylic acid ester copolymers in water with the commercial name
"Flexbond.RTM.".
[0016] Regardless of the aforementioned production or lamination
process of the outer ply 2, the ply 3 facing the container is
produced or prepared in a further process step. It consists for
example of plastics in a monostructure or compound structure, the
thickness range from 10 to 100 microns being chosen. The plastics
can be chosen from the group polypropylene, polyethylene,
polyester, polyacrylate, polyamide, or polystyrene.
[0017] Then the inner ply 3 facing the container is provided on its
surface side 3" facing the container with a heat-sealable layer 5.
It can be made for example from a hot sealing wax or a peelable
plastic film. It is furthermore conceivable for the heat-sealable
layer 5 to be applied by coextrusion coating. It is important that
by choosing the heat-sealable compounds, their chemical composition
and the degree of their crosslinking in the heat-sealing process,
adhesion between the inner ply 3 and the container edge 8 is
produced such that it is greater than that adhesion which is
produced by the cold-sealing layer 4 between the plies 2 and 3 of
the cover element.
[0018] It is furthermore advantageous that the heat-sealable layer
5 is made with a rough surface, since this greatly facilitates the
unstacking of the cover elements which are conventionally stored on
top of one another in magazines. The execution of the surface-rough
heat-sealable layer 5 in the form of geometrically arranged spacers
6 is especially advantageous. These spacers, due to their
geometrical arrangement, enclose air in the likewise regularly
arranged intermediate spaces so that the aforementioned unstacking
process is additionally facilitated. A rapid unstacking process is
especially of great advantage when, as in the case of perishable
foods, they must be sealed especially carefully and airtight when
being packaged.
[0019] The inner ply 3 of the cover element 1, which ply is
produced for example in this way, can now have an inherently closed
surface, as is shown in FIG. 1.
[0020] According to the embodiments as shown in FIGS. 2 and 3, the
inner ply 3 however can also have scoring 10 or perforations
11.
[0021] The scoring 1 0 is produced for example by slight punching
and is used to enable escape of the steam which may be formed when
microwave dishes are heated, without fouling the microwave
oven.
[0022] The inner ply can furthermore be provided with perforations
11 which constitute for example the form of a pour opening 12. It
is formed in a partial opening process and for large package
contents also enables partial removal of the packaged material.
[0023] Another possible embodiment of the element which is punched
out in a cover shape is shown in FIG. 4. Here the inner ply 3
facing the container has the shape of a broken lattice 14. This
lattice 14 consists of lengthwise filaments 15 and crosswise
filaments 16 which are formed from heat-sealable plastics, for
example from polypropylene, polyethylene, polyester, polyacrylate,
polyamide, or polystyrene. The lattice breaches 17 which are formed
between the lengthwise and crosswise filaments 15 and 16 after
partial opening enable proportioned delivery of sprinkled packaged
material such as spices, salt or pepper in which the necessary
flavor protection is to be ensured during storage and even after
opening of the container.
[0024] After producing or preparing the outer ply 2 and the inner
ply 3, they are joined to one another over their surfaces sides 2'
and 3' which face one another by the cold-sealing layer 4 in a cold
lamination process. This takes place for example in a lamination
station consisting essentially of a laminating roller pair, the
plies 2 and 3 each being brought near one another on a roller
surface such that the cold-sealing layer 4 which is attached for
example to the ply 3 is facing the surface side 3' of the ply 3
which is guided over the second laminating roller. Due to the
contact pressure which is formed in the roll gap, at room
temperature via the cold-sealing layer 4 an adhesive connection
takes place over the surface sides 2' and 3' of the plies 2 and 3.
Since the lamination process takes place at room temperature, the
heat-sealable layer 5 remains in the deactivated state, i.e. no
crosslinking reactions of any kind which cause adhesion which is
undesirable in this stage take place.
[0025] The plies 2 and 3 are now connected over their surfaces 2'
and 3' by the cold-sealing layer 4. This combination is stored as
rolled goods from which the elements for sealing can be punched out
in the corresponding cover shape. In doing so there can also be
formation of an opening aid, for example a pull tab 9, 9', at
locations free of cement. These cover elements 1 which are
ordinarily stored in magazines can now be used for other
applications, i.e. for sealing of containers 7. The containers 7
which can be filled with yoghurt, but also free-flowing packaged
materials such as spices, salt or pepper, are continuously sealed
with the elements 1 which are punched out in a cover shape as
claimed in the invention in a heat sealing process. By using
pressure at an elevated temperature the chemical compounds in the
heat-sealable layer 5 are activated such that adhesion is produced
in the range of greater than or equal (.gtoreq.) 5 N/15 mm
(measured according to DIN EN 28510-1 "Peel test for
flexibly/rigidly cemented samples") between the cover element 1 and
the container edge 8. This adhesion even after partial opening of
the container 7 results in that it is sealed at least partially
airtight. To open it, as is shown in FIGS. 1 to 4, the pull tab 9
which is located in the outer ply 2 is gripped and pulled in the
direction of the arrow F1. The adhesion between the plies 2 and 3
is overcome by the tearing force which is produced so that the
outer ply 2 can be pulled entirely or partially off the underlying
ply 3. So that in this opening process the cover element 1 can in
fact be partially peeled off, the adhesion between the outer ply 2
and the inner ply 3 is in the range from 0.2 to 4.5 N/15 mm
(measured according to DIN EN 28510-1 "Peel test for
flexibly/rigidly cemented samples").
[0026] In order to be able to measure the average peeling force
which is a characteristic quantity for the adhesion on the one hand
between the container edge 8 and the inner ply 3 and on the other
hand between the outer ply 2 and the inner ply 3, to perform the
peel test, samples of the compound partners, specifically the
container material and the inner ply 3 on the one hand and the
inner ply 3 and the outer ply 2 on the other, are produced in the
form of partial combination. Thus, as claimed in the invention
there is a partial combination of the container material 7, the
heat-sealable layer 5 and the inner ply 3 and a second partial
combination of the inner ply 3, the cold-sealable layer 4 and the
outer ply 2. For the peeling test, 15 mm wide and roughly 300 mm
long strips are cut out of these partial combinations in the
running direction. Then the compound partners are separated from
one another on the ends of the samples by hand so that the free
ends can be clamped in the clamping means of a tensile testing
apparatus, for example from the Zwick company. The test proceeds at
a pulling rate of 100 mm/min, a clamped length of a maximum 50 mm
and a pulling angle of 90.degree.. The measurement result or the
variation of the peeling strength (adhesion) is either read on the
tensile testing apparatus or is recorded with a diagram recorder.
The average values in N/15 mm are computed from the results of each
test series.
[0027] As is shown in FIG. 2c, it will be necessary to pull off the
entire ply 2 from the ply 3 since this embodiment of the cover
element 1 as claimed in the invention is suited for sealing of
microwave containers. Here the ply 2 which consists for example of
aluminum will be pulled off before use in the microwave so that
aluminum does not disrupt or prevent the passage of microwaves. The
steam which forms during heating can escape through the scoring 10
so that fouling of the microwave oven is prevented.
[0028] When the container 7 is partially opened, as is shown in
FIG. 3c, however by applying the tearing force F1 at the same time
a pour opening 12 is formed. This takes place by making a tear
along the perforations 11 so that on the outer ply 2 which has been
pulled off the ply 3 the corresponding shape of the pour opening 12
remains adhering. In this embodiment it is sufficient for the outer
ply 2 to be pulled off only partially at least in the area of the
pour opening 12 in order to enable partial removal of the packaged
material via this pour opening 12 for the consumer. For further
storage it is possible, by pressing the outer ply 2 against the ply
3, to ensure a type of resealability of the package. This takes
place by the corresponding selection of the cold-sealing layer 4
which can be present for example in the form of a
pressure-sensitive cement.
[0029] Even in the application as is shown in FIG. 4b, by pulling
on the pull tab 9 in the direction of the arrow F1 at least in part
the lattice-shaped structure 14 is exposed. By means of the lattice
breaches 17 a free-flowing packaged material, for example spices,
salt or pepper, can be removed. In this form of packaging it will
also be sufficient for the outer ply 2 to be only partially pulled
off the underlying ply 3.
[0030] In summary, it can therefore be stated that by differently
setting the adhesion between the plies 2 and 3 of the element which
is punched out in a cover shape as claimed in the invention on the
one hand and the adhesion between the container edge 8 and the
cover element surface 3, an opening mechanism can be initiated in a
purposeful manner such that the plies 2, 3 of the cover element 1
can be pulled off from one another in whole or in part. If the
outer ply 2 is pulled completely off the inner ply 3, for example
the scoring 10 on the inner ply 3 is exposed. If at this point
packaged material which is suited for heating in microwave ovens is
stored in the container 7, the steam which is conventional during
heating can escape through the exposed scoring 10 so that unwanted
fouling of the microwave oven is prevented.
* * * * *