U.S. patent application number 10/506818 was filed with the patent office on 2005-09-15 for single-use one-way valve for food package that emits sound signal at sufficient heating.
Invention is credited to Haamer, Joel.
Application Number | 20050199630 10/506818 |
Document ID | / |
Family ID | 20287290 |
Filed Date | 2005-09-15 |
United States Patent
Application |
20050199630 |
Kind Code |
A1 |
Haamer, Joel |
September 15, 2005 |
Single-use one-way valve for food package that emits sound signal
at sufficient heating
Abstract
The present invention concerns a single-use valve (1) for
mounting on a package (2), particularly food packages the contents
which are to be heated in a microwave oven (3). The valve (1) is
arranged to open in response to an excess pressure generated inside
the package (2) upon heating of said package (2). The valve
comprises an opening (4) formed in the package (2), on top of which
opening (4) an adhesive layer (5) is applied. The valve (1) is also
arranged to emit a sound signal when subjected to said pressure
load.
Inventors: |
Haamer, Joel; (Nosund,
SE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 8910
RESTON
VA
20195
US
|
Family ID: |
20287290 |
Appl. No.: |
10/506818 |
Filed: |
April 27, 2005 |
PCT Filed: |
February 27, 2003 |
PCT NO: |
PCT/SE03/00325 |
Current U.S.
Class: |
220/367.1 ;
219/735; 220/373 |
Current CPC
Class: |
B65D 51/165 20130101;
B65D 81/3446 20130101 |
Class at
Publication: |
220/367.1 ;
220/373; 219/735 |
International
Class: |
B65D 051/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2002 |
SE |
0200801-9 |
Claims
1. A single-use valve for mounting on a package, particularly food
packages the contents of which are to be heated in a microwave
oven, said valve arranged to open in response to an excess pressure
generated inside the package upon heating of the latter, wherein
that valve comprises an opening formed in the package, and adhesive
layer being applied on top of said opening, and in that said valve
is arranged to emit a sound signal when subjected to said pressure
load.
2. A valve as claimed in claim 1, wherein said opening is in the
form of a slit.
3. A valve as claimed in claim 2, wherein said slit is
straight.
4. A valve as claimed in claim 1, wherein at least one portion of
the adhesive layer comprises and adhesive that is suitable for use
in conjunction with foodstuffs.
5. A valve as claimed in claim 1, wherein said adhesive layer is a
tape.
6. A valve as claimed in claim 5, wherein said tape is
resilient.
7. A valve as claimed in claim 1, wherein said adhesive layer is a
label.
8. A valve as claimed in claim 1, wherein said packaging material
in which said valve provided, consists of a non-directional
laminate.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a single-use valve intended
to be mounted on a package, particularly food packages the contents
of which are to be heated in a microwave oven, said valve arranged
to open in response to an excess pressure generated inside the
package upon heating of the latter.
BACKGROUND OF THE INVENTION
[0002] In food packages, for example of the kind that contain
heat-and-eat one-portion dishes and that are sold in refrigeration
and freezing compartments, respectively, to be heated or cooked to
ready-to-eat state in a microwave oven, the food product usually is
placed in a heat-resistant tray covered by plastic film. When the
package is to be heated, the plastic film is either removed or
apertures are pierced therein and the entire tray is then placed
inside the microwave oven. Because of the varying performance of
different types of microwave ovens and because the food product
absorbs microwave energy differently, depending on the composition
and the temperature of the food product, heating times vary
considerably. Consequently, it is difficult to give recommendations
to the consumer as to the exact heating times required to reach the
ready-to-eat state. The consumer therefore might have to open and
reopen the microwave door several times to convince himself that
the dish is completely hot or completely cooked. However, it is
difficult to establish whether all parts of the dish are hot or if
locally it is still cold, and this is due to the inherent
difficulty of microwave ovens to heat the food product evenly.
Over-heating of the food is not either recommendable, since in this
case the tray or the plastic film still positioned thereon may melt
locally and ruin the food, or since overheating makes the food
soggy, over-cooked and unpalatable. The consumer therefore should
remain beside the microwave oven during the heating in order to
check when the food product has reached the ready state.
SUMMARY OF THE INVENTION
[0003] The object of the present invention therefore is to remove
this problem.
[0004] This object is achieved by means of a valve of the kind
defined in the introduction, possessing the characteristic features
defined in claim 1. Preferred embodiments of the valve appear from
the claims depending on claim 1.
[0005] The present invention relates to a single-use valve, which
is intended for mounting on a package, particularly on food
packages, the contents of which are to be heated in a microwave
oven. The valve is arranged to open in response to an excess
pressure generated in said package as the latter is being exposed
to heat. The inventive valve is arranged to emit a sound signal
when subjected to said pressure load. According to the teachings of
the invention, the valve is arranged on a package intended to hold
food products that are to be cooked/heated by the consumer until
they reach a ready-to-eat state. This kind of package is commonly
used for example as single-portion packages holding lunch or dinner
dishes. The valve does not open until a predetermined water-vapor
pressure is reached inside the package. Inside the package,
equalization of temperature takes place as hot water-vapor
condenses on cold areas of the product (the cold-wall principle).
Not until the entire product has reached about 100.degree. C. on
the surface is it possible for an excess pressure of vapor to
generate inside the package. The magnitude of the valve-opening
pressure could be determined on the basis of the resiliency of the
valve material, the size of the valve opening or the melting point
of the adhesive. The valve emits a sound signal as water vapor
flows through the valve. The sound signal indicates to the user
that the food product has reached the ready state. In this manner
is achieved not only the even heating results aimed for to ensure
that some zones of the food product do not remain cold but also the
user is given an audible indication that the dish is ready. The
user need not open the microwave-oven door to ascertain the
condition of the dish but could attend to other matters in the
meantime.
[0006] Alternatively, the valve is an indication of fracture, a
slit or an aperture across which an adhesive layer is disposed. The
adhesive layer is arranged in a manner ensuring that it is forced
to move, when a flow of air and vapor exits through the valve, in
response to which a sound signal is generated.
[0007] The valve preferably is configured as a slit formed in the
package, on top of which slit an adhesive layer is placed.
[0008] At least one part of the adhesive layer is formed with an
adhesive of a kind that is suitable for use together with
foodstuff, since the invention is primarily intended for food
packages.
[0009] It is likewise suitable that the adhesive layer is a tape,
preferably of a resilient kind to allow it to adapt itself to the
movements of the package material during handling and not disengage
itself from the support.
[0010] The adhesive layer could likewise be a label, thus
minimizing the consumption of material as well as the amount of
labor required to mark the product in outlet stores.
[0011] It is advantageous if the packaging material on which the
valve is provided consists of a non-directional laminate. In a
directional material, a slit would cause a rent to develop in the
material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention will be described in the following in more
detail with reference to the accompanying drawings, which for
exemplifying purposes show presently particularly preferred
embodiments of the invention. In the drawings:
[0013] FIG. 1 is an overall view of a package having a valve in
accordance with the present invention.
[0014] FIG. 2 is a cross-sectional view showing two different
stages of the process of heating a package having a valve in
accordance with the present invention. FIG. 2a shows the package in
a cold state and FIG. 2b the package in a heated state.
[0015] FIG. 3 is a perspective view, showing a microwave oven.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The food package 2 of FIG. 1 consists of a tray 7 holding a
food product 8. A packaging material 6 in the form of a
non-directional laminate is positioned on top of the tray 7 in
order to protect the food product 8 from external manipulation
during the production and distribution stages. The tray 7 as well
as the laminate 6 consist of heat-resistant materials, since their
intended function is to enclose food that is to be heated. The
laminate 6 is welded to the tray 7 to produce a strong and
impermeable seam. The valve 1 in accordance with the present
invention is formed in the non-directional laminate 6. The valve 1
is an opening 4 passing through the laminate. A resilient tape 5
the adhesive of which is suitable for use together with foodstuff
is placed on top of the opening 4. The location of tape 5 is chosen
such that the distance between the opening 4 and the longitudinal
edges of the tape 5 in conjunction with the strength of the
adhesive of the tape 5 ensures that an excess water-vapor pressure
generated inside the package 2 as the food product contained
therein is being heated, is powerful enough to force water vapor
out through the opening 4 while passing between the tape 5 and the
laminate and in doing so generate a sound signal owing to the
vibration of the tape. Alternatively, a slit may be formed in the
adhesive layer/tape 5 to prevent the longitudinal edge thereof to
open up in an uncontrolled manner.
[0017] FIG. 2a shows the same food package 2 as FIG. 1. The food
product 8 is positioned in the tray 7, which is covered by the
laminate 6. The valve 1, in the form of opening 4 and tape 5, is
provided in the laminate 6. This drawing figure shows the food
product 8 in the condition in which it is sold to the consumer,
i.e. deep-frozen, refrigerated or stored in some other way. FIG. 2b
shows the food package 2 while being exposed to microwaves for
heating purposes and in the state when the food product 8 is
sufficiently warm for the water vapor to create an excess pressure
inside the package 2 that is powerful enough to open the valve 1
and generate a sound signal.
[0018] FIG. 3 finally shows a microwave oven 3, in which the food
package 2 may be positioned for heating of the food product 8.
[0019] As will be realized numerous modifications of the embodiment
described above are possible within the scope of protection as
defined in the appended claims. For example, instead of consisting
of a tray 7 and a non-directional laminate 6, the food package 2
could be formed entirely of a plastic film or some other material
suitable for storage of food 8. However, some part of the package 2
should consist of a type of non-directional laminate 6 that is
suitable to form the valve 1 in accordance with the invention. The
food package 2 could hold for example refrigerated or deep-frozen
products. The size and shape of the tape 5 or label are not
restricted to the shown embodiment.
[0020] The function of the valve 1 remains the same also if an
indication of fracture is impressed into the non-directional
laminate 6 or an etching is made therein in such a manner that the
laminate 6 still is in one piece with no through-passage opening
formed in the material. The indication of fracture means that the
packaging material 6 offers perfectly satisfactory protection to
the contents inside the package 2 without having any contact with
the adhesive layer up to the point, when the package 2 is heated.
In the heating process, water vapor forms in the usual manner, and
upon a predetermined excess pressure inside the package 2 it breaks
the indication of fracture, whereby an opening 4 is formed, and
vapor is forced outwards and together with the adhesive layer it
generates the sound signal. The strength of the package material 6
itself is sufficient to prevent the material from bursting should
an indication of fracture not have been provided. If for some
reason the material should burst anyway, no sound signal would be
emitted, since in all likelihood an uncontrolled rift in the
material would be of a configuration that cannot produce a
sound.
[0021] In addition it is possible to provide a sound-emitting
element of a flute-like type on top of the opening 4 in the package
2. This sound-emitting element likewise would serve to indicate
when the food product 8 inside the package 2 is heated to the
ready. It is likewise possible to give the slit in the package
another shape than a straight one, for instance a V-shape.
* * * * *