Method of forming score lines on blank, method of manufacturing package using same, and package

Abstract

A blank forming step for forming a sheet-shaped resin blank able to be formed into a box by folding and bending, and a score line forming step of forming score lines in score line forming areas of the blank which are to be bent to form outer edges of the box, to extend in the direction in which the outer edges should extend. In the score line forming step, the score lines are formed in a manner causing grooves to be produced on the back side of each score line forming area, along the score lines, through plastic deformation. The blank therefore does not undergo tensile stress pulling on the blank to either side of each groove, and thus, does not undergo warping as a whole. The blank thus retains its sheet shape and can be steadily supplied to a packaging machine.

Description

TECHNICAL FIELD[0001]The present invention relates to a method of forming score lines on a blank, a method of manufacturing a package using same, and a package.background art[0002]Generally, packages of this type are called hinged-lid packages. The hinged-lid package is cuboidal in shape and has four longitudinal angular edges. The package with angular edges does not fit comfortably in the hand of a user who holds the package. The package with rounded edges in place of angular edges is therefore preferable. A blank (plastic sheet) for forming a package with rounded edges is known (see patent document 1, for example).[0003]According to patent document 1, score lines are formed on the blank by pressing blades against the blank, and the resulting score-lined areas are bent into rounded edges.[0004]The forming of score lines in the manner shown in patent document 1, however, stretches the score-lined surface, so that the blank warps in the manner that the score-lined surface bulges. Suc...

AI Technical Summary

Benefits of technology

[0015]The method according to the present invention comprises a blank forming step of forming a blank able to be formed into a box by folding, and a score line forming step of forming score lines in areas of the blank which are to be bent to form outer edges of the box, to extend in a direction in which the outer edges should extend, and in the score line forming step, the score lines are formed in a manner causing grooves to be produced on a back side of each score line forming area, along the score lines, through plastic deformation. The score lines are thus formed on one side of the blank which is to form the outer surface of the box, and the forming of the score lines on one side of the blank simultaneously and automatically causes the production of grooves on the other side of the blank through plastic deformation. The blank therefore does not undergo tensile stress pulling on the blank to either side of each groove, and thus, does not undergo warping as a whole. Since the blank retains its sheet shape, it can be steadily supplied to a packaging machine. From the blank prevented from warping, a package can be formed without distortion.

[0016]When the blank is configured to have a main section and a sub-section so as to be applied to a cigarette package (so-called hinged-lid package), the resulting cigarette package has rounded edges formed by bending the score-lined areas. Such package fits comfortably in the hand.

[0017]In the blank forming step, a printed layer is formed on the side of the blank opposite to the score line forming area side, which means that the score lines are not formed directly on the printed layer.

[0018]When made of polyethylene terephthalate, the blank is easy to handle and easy to form score lines thereon.

[0019]A cigarette package with rounded edges can be produced from the blank having undergone the score line forming step, by bending the blank with the score-lined surface outside, thereby forming the blank into a box, where each score-lined area can be bent into a rounded edge utilizing the score lines. The cigarette package with rounded edges fits comfortably in the hand.

Problems solved by technology

The package with angular edges does not fit comfortably in the hand of a user who holds the package.

Such warped blank is not allowed to be supplied to a packaging machine to package items, such as cigarettes, in the blank.

If the package is formed using such warped blank, the inner side of each rounded edge, namely the back side of each score-lined area stores the power to return to the original state, so that the whole package is swollen and distorted.

Such distorted package is regarded as poor-quality and thus cannot be put on the market.

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