Engineering with regard to the production of food container
Conventional food containers are made of paper sheets with the inner surfaces coated with a polymer compound. A food container has four lateral side portions. Between the lateral side portions are corner-edge sections. The lower side of each lateral side portion is made into a base portion. One side portion of the corner-edge portion is made into a side flank. The lateral edges of the lateral side portion and the side flank are sealed together by attaching the lateral regions of the lateral side portion coated with the polymer compound onto an uncoated side flank. The sealing between the surface coated with a heat resisting material and the uncoated surface cannot prevent leakage or permeation of food contained in the food container out along the lateral contact surface which has been well sealed.
The food container according to the present invention is made of a paper sheet which includes a base portion having four sides connected to the lateral side portions along a folding line in an overlapping manner. Between each lateral side portion is a side flank which is divided into two portions along a folding line. The outer rim portions of a pair of opposite lateral side portions function as inner cover portions similar to cut-end gables. The outer rim portions of another pair of opposite lateral side portions function as outer cover portions. Forming a food container by folding according to the present invention has an advantage in preventing leakage of food contained in the food container out along the lateral contact surface sealed and attached together since it is a double layer sealing structure which can prevent leakage effectively.
An object of the present invention is to provide an improved food container which can prevent leakage of food contained in the food container out along the lateral contact surface sealed and attached. This can be achieved by making the lateral contact surface of the food container sealed and attached together on the surface coated with a polymer compound. This can prevent leakage effectively.
The outer rim portions of a pair of the opposite lateral side portions 4 function as inner cover portions 7 with a shape similar to a cut end gable. The lateral side portions 4 and the inner cover portions 7 on both sides are connected by folding along the folding line 3. The outer rim portions of another pair of the opposite lateral side portions 4 function as an outer cover portions 8 and an outer cover portion 9. The lateral side portions 4 and the outer cover portion 8 together with the outer cover portion 9 are also connected together by folding along the folding line 3.
The outer cover portion 8 is similar in shape to a cut end gable with a cutting line 10 for engaging a tongue portion 11 of the outer cover portion 9. This outer cover portion 9 is similar in shape to a rectangle with cut angles to conform with the outer cover portion 8 when inserted and attached together. The outer region of the outer cover portion 9 is provided with a tongue portion 11 for inserting into the cutting line 10 of the outer cover portion 8.
As described in the detailed description of the invention.