FIELD OF THE INVENTION

The present invention relates to a paperboard food container which is made by a single piece of paperboard and the paperboard is exposed to high humidity before being molded.

BACKGROUND OF THE INVENTION

A conventional paperboard food container for receiving food is developed for a period of time and includes a common feature of requiring a lot of parts which are then glued with each other to form desired shapes. In order to have better structural strength, the parts are made to include specific shapes such as leaves, or folding areas by which different parts can be glued with each other. A typical paperboard food container includes a base with a plurality of separation ribs attached to the base so as to receive different types of food therein. The base includes a flange folded upward along its periphery and each rib includes connection leaves so as to be glued to the base. Different types of cutting machine are needed to cut the paperboard into desired shapes and sizes. Each cut part is then molded or folded to obtain the desired shape in three dimensions, and the parts are then glued together to form the final products. It is noted that leakage is a common shortcoming for the conventional paperboard food containers between the glued parts and the conventional method produces a lot of unused portions of the paperboard because too many small parts are cut from a paperboard.

The present invention intends to provide a paperboard food container that is made from a single piece of paperboard which is molded into desired shape while the density of the paperboard is remained the same.

SUMMARY OF THE INVENTION

The present invention relates to a paperboard food container made of an integral piece of paperboard and including a base with peripheral wall and at least one ridge extending from a top surface of the base. Each corner of the base is a rounded corner. The paperboard food container is made by the method which includes a step of exposing the paperboard in high temperature of vapor to increase moisture content of the paperboard; a step of molding the paperboard, and a step of trimming the paperboard. The paperboard food container includes a base with periphery wall and rounded corners. At least one separation ridge extends from a top surface of the base.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the paperboard food container of the present invention;

FIG. 2 is a perspective view of a second embodiment of the paperboard food container of the present invention;

FIG. 3 is a perspective view of a third embodiment of the paperboard food container of the present invention, and

FIG. 4 shows the steps of the method for making the paperboard food container of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 4, the method of first embodiment of the paperboard food container 10 of the present invention comprises the following steps:

- step 1: preparing a piece of paperboard;
- step 2: exposing the paperboard in high temperature of vapor to increase moisture content of the paperboard so that the paperboard has better ductility;
- step 3: molding the paperboard in step 2 under high temperature so as to have the peripheral wall which defines a recessed area for receiving food, and
- step 4: trimming the paperboard in step 3.

Referring to FIGS. 1 to 3, the paperboard food container 10 made by the method are in shape of rectangle or circular and the number of the containers can be optimized in each sheet of paperboard so as to reduce the useless portion. It is noted that the paperboard food container 10 has rounded corners which are made by the setting of the molds and the separation ridges can also be easily made at desired positions.

Because the paperboard food container 10 is made of an integral piece of paperboard and the separation ridges are also integral to the base so that no leakage should be worried. A plurality of reinforcement protrusions 11 are formed in each of the corners so as to reinforce the structural strength of the container 10 and although the thickness of the reinforcement protrusions 11 becomes thinner, the density of the reinforcement protrusions 11 is remained the same as that of the base. The paperboard food containers 10 can be easily made in mass production with minimum waste.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.