U.S. patent application number 12/086752 was filed with the patent office on 2009-07-02 for package valve system.
Invention is credited to Gunnar Olsson.
Application Number | 20090166362 12/086752 |
Document ID | / |
Family ID | 37491823 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090166362 |
Kind Code |
A1 |
Olsson; Gunnar |
July 2, 2009 |
Package Valve System
Abstract
A valve system for a container (4, 5), especially for food
containers whose contents are intended to be heated, comprises an
adhesive layer (3) arranged over an opening portion (6) in the
container (4). The adhesive layer (3) is arranged to at least
partly release the container (4) adjacent an opening portion (1) in
the adhesive layer in case of overpressure and thus form an opening
to allow a flow out of the container (4, 5) and, in this
flowing-out, emit an acoustic signal by means of said opening
portion (1) in the adhesive layer (3) which is made to oscillate by
the flow. The valve system comprises at least a second opening
portion (2) arranged, in heating of the contents of the container
(4, 5), to open before the above-mentioned opening portion (1) in
the adhesive layer (3).
Inventors: |
Olsson; Gunnar; (Vastra
Frolunda, SE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 8910
RESTON
VA
20195
US
|
Family ID: |
37491823 |
Appl. No.: |
12/086752 |
Filed: |
February 7, 2007 |
PCT Filed: |
February 7, 2007 |
PCT NO: |
PCT/SE2007/000111 |
371 Date: |
July 18, 2008 |
Current U.S.
Class: |
220/367.1 ;
220/745 |
Current CPC
Class: |
B65D 81/3453 20130101;
B65D 77/225 20130101; B65D 2205/00 20130101 |
Class at
Publication: |
220/367.1 ;
220/745 |
International
Class: |
B65D 81/34 20060101
B65D081/34; B65D 51/16 20060101 B65D051/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2006 |
SE |
0600306-5 |
Claims
1. A valve system for a container, especially for food containers
whose contents are intended to be heated, said valve system
comprising an adhesive layer arranged over an opening portion in
the container, the adhesive layer being arranged to at least partly
release the container adjacent an opening portion in the adhesive
layer in case of overpressure and thus form an opening to allow a
flow out of the container and, in this flowing-out, emit an
acoustic signal by means of said opening portion in the adhesive
layer which is made to oscillate by the flow, wherein the valve
system comprises at least a second opening portion arranged, in
heating of the contents of the container, to open before the
above-mentioned opening portion in the adhesive layer.
2. A valve system as claimed in claim 1, in which said second
opening portion is arranged in the adhesive layer.
3. A valve system as claimed in claim 2, in which said second
opening portion comprises a slit in the adhesive layer.
4. A valve system as claimed in claim 3, in which the slit is
straight.
5. A valve system as claimed in claim 4, in which slits are aligned
with each other.
6. A valve system as claimed in claim 1, in which the opening
portion of the container is a slit.
7. A valve system as claimed in claim 1, in which said second
opening portion is arranged closer to the opening portion in the
container than said first opening portion in the adhesive
layer.
8. A valve system as claimed in claim 1, in which said second
opening portion is arranged to close when said first opening
portion in the adhesive layer opens.
9. A valve system as claimed in claim 1, in which at least part of
the container is perforated.
10. A valve system as claimed in claim 1, in which said second
opening portion consists of perforations in the container.
11. A valve system as claimed in claim 1, in which the adhesive
layer is resealable.
12. A valve system as claimed in claim 1, in which said first
opening portion comprises a flap in the adhesive layer.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a valve system for a
package or container, especially for food containers whose contents
are intended to be heated, said valve system comprising an adhesive
layer arranged over an opening portion in the container, the
adhesive layer being arranged to at least partly release the
container adjacent an opening portion in the adhesive layer in case
of overpressure and thus form an opening to allow a flow out of the
container and, in this flowing-out, emit an acoustic signal by
means of said opening portion in the adhesive layer which is made
to oscillate by the flow.
BACKGROUND ART
[0002] In a food container of, for instance, the type that contains
prepared one person dishes and that is sold in refrigerated and
frozen-food counters to be heated or finally cocked in a microwave
oven, the food is usually placed in a heat-resistant tray and
covered with a plastic film. For heating, either the plastic film
is removed or it is punctured and then the entire tray is placed in
the microwave oven. Due to the fact that different types of
microwave oven have different performances and the food absorbs
microwave energy in different ways due to composition and
temperature, the time for heating varies significantly. It is
therefore difficult to give the consumer recommendations as to how
long the food is to be heated to be ready. For the consumer, this
may require that the microwave oven be opened several times to
allow him to sense whether the food is thoroughly hot or ready
cocked. However, it is difficult to sense whether all the food is
hot or whether the food is locally still cold due to the inherent
difficulty of the microwave oven of evenly heating the food. Nor
should the food be extra heated since the tray or the remaining
plastic film can then locally melt and destroy the food or since
extra heating makes the food soft, overcooked and unpleasant to
eat. This makes it necessary for the consumer to remain close to
the microwave oven throughout the heating in order to check whether
the food is ready to eat.
[0003] One way of eliminating the above drawback is to use a valve
which is adapted to open at an overpressure arising in the
container during heating and which besides is arranged to emit an
acoustic signal in said opening. The valve consists alternatively
of an indication of fracture, a slit or a hole, over which an
adhesive layer is arranged. The adhesive layer is arranged to be
forced to move when a flow of steam/gas passes out of the valve,
whereby an acoustic signal occurs. A common variant of such a valve
comprises a slit in the container, over which slit an adhesive
layer is arranged, which adhesive layer at least in a portion is
provided with an adhesive suited for use with food since the
invention in the first place aims at food containers. Moreover, the
adhesive layer usually is an adhesive tape, preferably elastic, so
as to be able to follow the motions of the container material
during handling and not release the base.
[0004] However, it has been found difficult to control the opening
of the valve. Different foodstuffs generate different amounts of
steam while at the same time a valve as stated above practically
always opens at the same overpressure. As a result, some foodstuffs
are thus not sufficiently heated when the valve first emits an
acoustic signal. In experiments of controlling the opening using an
adhesive with different degrees of adhesiveness, it has been found
that with a slightly stronger adhesive, instead the joints of the
container crack before the valve opens. It is thus a very narrow
range in which it is possible to control opening. Even if it is
theoretically possible to control when a valve is to open using the
adhesive, this means at the same time that a unique valve is
required for each type of food. Consequently this is too
complicated if the costs are to be kept down.
SUMMARY OF THE INVENTION
[0005] The object of the present invention therefore is to
alleviate the above problems.
[0006] This object is achieved by a valve system of the type stated
by way of introduction being given the features as defined in claim
1. Preferred embodiments of the valve system are stated in the
claims dependent from claim 1.
[0007] The present invention is described based on valve systems
for food containers. Foodstuffs normally generate steam when
heated, bur the valve system according to the present invention can
also be used for other types of containers where the contents are
to be heated and, instead of steam, a gas can be used to cause the
opening.
[0008] The present invention is a valve system for a container,
especially for food containers whose contents are intended to be
heated, said valve system comprising an adhesive layer arranged
over an opening portion in the container, the adhesive layer being
arranged to at least partly release the container adjacent an
opening portion in the adhesive layer in case of overpressure and
thus form an opening to allow a flow out of the container and, in
this flowing-out, emit an acoustic signal by means of said opening
portion in the adhesive layer which is made to oscillate by the
flow, wherein the valve system comprises at least a second opening
portion arranged, in heating of the contents of the container, to
open before the above-mentioned opening portion in the adhesive
layer. When heating a container with its contents, the pressure
first rises until said second opening portion opens, and after that
the pressure falls. In the continued heating, the temperature thus
rises and the flow out of the container increases and causes after
a while the opening of said first opening portion. In other words,
said second opening portion is arranged to open at a lower
temperature than said first opening portion.
[0009] This second opening portion is thus designed so as not to
emit an acoustic signal when gas or steam flows out of this
portion. When heating the container with its contents, steam is
generated depending on the supplied energy and the contents of the
container after different periods of time. In most cases, the food
is not sufficiently heated as the first steam is generated. The
idea of the invention is to release this first steam through an
opening that does not generate any sound. Once the food is heated
to the correct temperature, a much greater amount of steam is
generated, which the opening first formed cannot manage. This steam
therefore presses up the adhesive layer so that the specially
designed opening portion is made to oscillate due to the flow of
steam. This means that an acoustic signal is not generated until
the food is sufficiently heated. The expression "adhesive layer" is
adapted to include, for example, an adhesive tape or a
self-adhesive label.
[0010] It is most common to use microwave ovens for heating as
described above, but other types of heating will work as well, such
as a convection oven (steam box/steam oven).
[0011] In a variant of the invention, said second opening portion
is arranged in the adhesive layer. This allows a relatively simple
solution since the actual container has to be provided with only
one opening portion over with the adhesive layer is arranged.
[0012] An alternative is to form said second opening portion in the
adhesive layer as a slit, most advantageously a straight slit and
preferably more than one slit, which, for example, can be aligned
with each other to form a "dashed line". Slits are relatively easy
and inexpensive to make in an adhesive layer.
[0013] In one embodiment of the invention, the opening portion in
the container is a slit. The slit can be formed in various ways,
for example a straight slit, an arcuate slit or two or more slits
intersecting each other.
[0014] When said second opening portion is arranged in the adhesive
layer, it is suitable for the second opening portion to be arranged
closer to the opening portion in the container than said first
opening portion in the adhesive layer. Theoretically, said second
opening portion could instead be arranged at a greater distance if,
for example, adhesives with different degrees of adhesiveness are
used. An alternative embodiment could further be obtained with two
adhesive layers, one adhesive layer comprising the opening portion
that is to open for the first steam produced in heating, and the
second layer would then comprise the opening portion that generates
an acoustic signal in producing a great amount of steam when the
contents in the container are ready to eat.
[0015] In one embodiment, said second opening portion is arranged
to close when said first opening portion in the adhesive layer
opens. If all the flow out of the container passes through the
opening that generates the acoustic signal, a louder acoustic
signal is obtained, which in some contexts can be advantageous.
[0016] In an alternative embodiment, at least part of the container
is perforated. Film that is perforated is normally used for, for
example, vegetables which, without being heated in an oven,
sometimes generate gases, that is an overpressure in the container
which without these microopenings could destroy the entire
container. A perforated portion of the container could be used to
supplement the valve system according to the present invention.
Alternatively, it could constitute said second opening portion,
that is the opening portion in the valve system that does not
generate an acoustic signal.
[0017] In some ranges of application, it is advantageous for the
adhesive layer to be resealable. In certain production of, for
example, one person dishes, the foodstuffs are prepared in their
final containers in microwave tunnels. These containers should then
be provided with a valve that can close after heating to prevent a
flow into the container from occurring in the subsequent
refrigeration when a negative pressure is automatically generated
in the container. The same valve is used once more when the final
user heats the container with its contents.
[0018] Preferably, said first opening portion in the adhesive layer
has the shape of a flap. This shape has been found particularly
convenient for generating an acoustic signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will now be described in more detail with
reference to the accompanying drawings which by way of example
illustrate currently preferred embodiments of the present
invention.
[0020] FIG. 1a is a simple exploded view of a valve system
according to an embodiment of the present invention.
[0021] FIG. 2a is a perspective view of a portion of the valve
system according to the present invention in a first heating
phase.
[0022] FIG. 2b is a side view of a container with a valve system
according to FIG. 2a and in the same heating phase.
[0023] FIG. 3a is a perspective view of a portion of the valve
system according to the present invention in a second heating
phase.
[0024] FIG. 3b is a side view of a container with a valve system
according to FIG. 3a and in the same heating phase.
[0025] FIG. 4a is a perspective view of a portion of the valve
system according to the present invention in a third heating
phase.
[0026] FIG. 4b is a side view of a container with a valve system
according to FIG. 4a and in the same heating phase.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] A first opening portion 1 and a second opening portion 2 in
an adhesive layer 3 are shown in FIG. 1. The adhesive layer is
adapted to be placed over a plastic film 4 which in turn is to
cover a tray 5. In the plastic film 4, a slit 6 is formed, which in
this embodiment is the opening portion of the container.
[0028] FIGS. 2a and 2b illustrate how the adhesive layer 3 has
started to release the plastic film 4 around the opening 6 in the
plastic film 4 when a certain overpressure has occurred in the
container. FIGS. 3a and 3b illustrate the next phase in heating
when the overpressure in the container has made the adhesive layer
3 release the plastic film 4 so that ducts are formed all the way
to three slits 2, which have formed three openings through which
steam can flow. FIGS. 4a and 4b illustrate the valve system when
the contents of the container are sufficiently heated. In this
phase, a greater flow out of the container than in the previous
phase has been produced, which has made the adhesive layer 3
further release the plastic film 4 so that a duct is formed all the
way to a flap-shaped slit 1. Due to the flow, the "flap" is made to
oscillate, which oscillating generates an acoustic signal. The
relative position of the slit 1 and the slits 2 results in the
openings formed by the slits 2 being closed when the slit 1 forms
an opening.
[0029] It will be appreciated that many modifications of the above
described embodiment are conceivable within the scope of invention
as defined in the appended claims. For example, as described, the
slit or slits in the adhesive layer which constitute the second
opening portion could, of course, be formed in other ways than as
straight cuts, for example with a wave shape or arch shape. It is
also possible to design both opening portions to generate sound,
although with, for example, different tones so that the first tone
signals that there is still some time left until the food is ready
to eat. An alternative would also be that, for example, one and the
same slit in the adhesive layer is used for opening in a first
phase, in which case the slit in additional heating opens further
so as to generate an acoustic signal or alternatively change the
character of the acoustic signal.
* * * * *