Patent Application
20100068352
Currently there are many types of packages in which food is purchased. It is often desirable to be able to heat and/or cook food in the same packaging in which it is purchased. This can prove challenging when the method of heating employs a microwave oven. When food is heated in a substantially closed container in a microwave oven, pressure builds within the package due to the production of steam. It is therefore advantageous to have a package that provides a mechanism that will allow the release of steam from the package to avoid rupturing the package.
Packages exist that allow heating and/or cooking of the food within the package in a microwave oven through the use of a vent. The most common of these packages are microwaveable popcorn packages. Typically, the microwaveable popcorn package has a preformed steam vent which has an opening at the same position where the package is to be opened once the popcorn is popped. This results in the consumer experiencing hot steam coming out from inside the package as the consumer opens the package.
Another type of package exists that employs a standard side seal on a microwaveable flexible pouch. Such a package is described in US Published Patent Application 2005/0276885. Once the side seal is formed in the pouch, an aperture is formed through the panels that make up the side seal. The aperture is to perform as a steam vent with the seal separating up to the aperture as steam pressure builds up in the package. The aperture also doubles as a way of hanging the pouch on a hanger or store display. However, it has been found that this seal with the aperture ruptures past the seal during microwave heating in a fin seal type package.
The present invention includes a package for containing food and heating food in a microwave oven. The package includes a fin seal, wherein the fin seal has an aperture positioned to act as a vent when the package and its contents are heated in a microwave oven. The aperture provides a reliable venting location so the user is alerted as to which portion of the packaging may expose the user to escaping high temperature steam.
A venting mechanism for a microwaveable flexible package is generally illustrated at 10 in
The package 12 in most aspects is a typical food package suitable for cooking food in a microwave. The package is made from a continuous sheet 13 of flexible polymeric film as illustrated in
For purposes of this application, the fin seal 14 is a seal that is formed by placing edge sections 22 and 24 of the sheet 13 on each other as the sheet 13 moves in the direction of arrow 15. The edge sections 22 and 24 are adhesively secured to each other using a conventional process that is well known. In doing so, the package 10 is sealed along the edge sections 22 and 24 to form a “fin” seal. The methods used to seal edge portions 22 and 24 include heat, ultrasonic or adhesive sealing techniques or any combination thereof.
Once the fin seal is formed, the film moving in the general direction of arrow 15 is folded to form folded edges 17 and 19 which then define opposing walls 18 and 20 of the package. The fin seal 12 generally lies flat adjacent the wall 18.
As further illustrated in
The top edge of the package 23 remains in an open position and will be sealed once the package is filled with food, such as vegetables.
The seal 12 is formed such that once steam is created during the microwaving process, and sufficient pressure is built up within the package, the fin seal will start to separate. The fin seal will start to separate until the separation reaches the vent hole 28. Once the separation of the fin seal reaches the vent hole 28, steam is released from the package.
Since the integrity of the fin seal is not compromised during microwave heating, the contents of the package stay within. In this way, the food being microwaved within the package does not escape the package. Due to the indicia warning of the location of the vent, the user of the microwave package knows where on the package that the steam is being vented, and can then avoid the hot steam coming out of the package.
In use, the package 10 containing food to be heated is placed in a microwave oven 30 as illustrated in
In a preferred embodiment of this invention, the fin seal 14 is about 12 mm wide and extends the entire length of one side of the package 10. The vent hole 11 should be of a size sufficient to allow steam to be released to eliminate further pressure building within the package. In a preferred embodiment, the vent hole 11 is circular in shape but other shapes are within the scope of this invention. Vent hole sizes ranging from 1.6 mm to 6.0 mm in diameter produced the best results.
To a certain extent, the rate of steam production within the package will be a function of the moisture content of the food product within. In view of this, the vent hole diameter may have to be adjusted to accommodate the amount of steam being produced and being vented during microwaving.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
