Packaging container for microwave oven

Abstract

A packaging container for a microwave oven. Completion of heating of the container contents and automatic opening of the container can be easily recognized. This can be achieved without requiring a special member and complex steps, but by processing wrapping materials constructing the packaging container. Also provided is a packaging container for a microwave oven, where danger, including spilling of the contents of the container and burning by touching an opening section occurring in heating by a microwave oven, can be avoided. Further provided is a packaging container for a microwave oven, sealed by heat-sealing plastic films and having a steam vent seal section having a weakened section. The steam vent seal section has mark emerging means, and when the steam vent seal section is separated and opened, the means shows different surface- and back face-wrapping materials constituting the steam vent seal section, enabling recognition of opening.

Description

TECHNICAL FIELD [0001] The present invention relates to a packaging container for a microwave oven such as a packaging pouch, a cup, or a tray filled with contents such as a retort food containing a liquid substance, a solid substance, or a mixture of them. The packaging container of the present invention is capable of automatically releasing water vapor or the like to be generated inside the packaging container, preventing the rupture and deformation of the packaging container, scattering of the content, and allowing one to easily recognize the fact that the packaging container is opened under heating in a microwave oven. BACKGROUND ART [0002] Heating of a packing container such as a packaging pouch, a cup, or a tray hermetically filled with a retort food, a frozen food, or the like in a microwave oven increases the pressure inside the pouch and a container due to water vapor or the like to be generated from contents under heating. The packaging container may tear, and the content ...

AI Technical Summary

Benefits of technology

The present invention provides a packaging container for a microwave oven that can automatically open when heated in the microwave, preventing rupture and deformation of the container and scattering of the contents. The container includes a vapor release seal part with a weakened part that can be easily recognized by a difference between the surface and back packaging materials. The mark developing means can be printed processing or other means that do not require a special member or complicated steps. The container is designed to be simple and cost-effective to manufacture and use.

Problems solved by technology

The packaging container may tear, and the content may scatter, to thereby make the inside of the microwave oven dirty or harm a human body by burning or the like.

However, such methods involve much time and effort for a general consumer.

Further, when these methods are applied, the methods have disadvantages in that a flavor of the contents cooked by heating is lost because the water vapor generated by microwave heating is immediately discharged out of the packaging container and a heat steaming effect of the water vapor on the content is reduced.

However, this method of judging the opening is hard to recognize and may cause one to ignore the opening of a packaging container.

However, each of those containers requires a step of using a high-cost, separate alarm whistle and coupling the alarm whistle.

Accordingly, there arises, for example, a problem in that the production process of each of the containers becomes complicated, which results in an increase in cost.

However, in such a packaging pouch, it becomes difficult to recognize a letter or symbol appearing upon opening unless an area of a portion to be provided with the hidden printing layer is equal to or larger than a certain value.

Therefore, it has not been possible to apply this technique to a vapor release seal part opening automatically upon heating of a packaging container for a microwave oven such as a packaging pouch, a cup, or a tray.

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