JP2002179077A - Overlap width for sealing envelope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a design of an overlap width and its forming method for realizing the unsealing of a sealed letter, which involves an unreversible and controlled breaking without using an edged tool or the like and irregularly breaking a sheet in the case where a sealed letter made of paper for information is unsealed on the receiver's side. SOLUTION: A rectangular envelope for a sealed letter is formed by using a wood-free sheet, which is within the range of 81 to 162 g per m2, or a coated sheet, and by applying a pressure-sensitive adhesive to a portion where one side or a plurality of sides are overlapped. In this case, a space having a distance of 0.5 to 10 mm from a portion to which the pressure-sensitive adhesive is applied is provided by a straight line or by a curved line at the whole edge or at part of an edge along an edge at an adhered portion of a joint by the pressure-sensitive adhesive. A cut having a depth of at most 1/2 of the thickness of the sheet is provided in both of or in one of the joint surfaces of the overlapping sheets, and the sheets are then joined to each other, thus forming the envelope.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a paper envelope used in the field of business communication and the like.

[0002]

In the case of a paper envelope in which information is communicated in a sealed state, a blade or the like is not used at the time of opening at the receiving side, and the paper is not broken in an irregular shape, and
It is intended to achieve opening with irreversible controlled destruction.

[0003]

2. Description of the Related Art Conventionally, a paper envelope is sealed with a pressure-sensitive adhesive or the like, and when opened, it is generally broken or cut with a blade. In some cases, cutting by a cutting tool is made more convenient by using a cut-out sewing line. In each case, the sealed letter leads to an irregular destruction of the original prototype. On the other hand, a method of realizing non-destructive opening using a pressure-sensitive adhesive using a pseudo-adhesive compatible product is also used. In this case, it is necessary to use a specified product which has been evaluated for the pressure-sensitive adhesive, and if the sealer cannot be specified, it becomes difficult to specify the conditions. It is virtually unusable in the application in question.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealed letter which can be easily opened at the time of opening and without breaking the sealed letter as much as possible irrespective of the kind of adhesive used for sealing the sealed letter.
For this reason, the present inventors have paid attention to the nature of delamination of paper, in general, the surface paper discoloration phenomenon, and have studied from the observation result that the destruction at the time of opening a sealed letter is due to the propagation of delamination at the bonding site. From there, a cut that cuts off the propagation of delamination at the bonding site is formed on a sheet of a certain thickness or more, specifically, in a range of 81 to 162 g per square meter.
The invention achieved by treating to a depth of / 2 or less has been established.

Next, the present invention will be described in detail based on an embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 shows a state in which a sealing portion of a general envelope is not yet sealed, and is constituted by paper 1 and paper 2.
The pressure-sensitive adhesive 3 is applied to the sealing portion, and a straight cut 5 is made along the edge of the pressure-sensitive adhesive. FIG.
1 shows a state in which the paper 2 of the sealed letter prepared in FIG. 1 is folded back and the paper 1 and the paper 2 are bonded with a pressure-sensitive adhesive, and the gap 4 is the inner surface of the sealed letter, and is opened in the pulling direction 6 when opening. Is explained. FIG. 3 shows a breakage line 7 of the paper 1, a pressure-sensitive adhesive 3, and a notch, which are assumed when the sealing portion bonded in FIG. It is a schematic diagram of No. 5. In this embodiment, the thickness 8 of the sheet is 0.15 mm, the depth 9 of the cut 5 is 0.07 mm, and the clearance between the pressure-sensitive adhesive 3 and the cut 5 is 1 mm. When an opening force is applied in the direction of 6 in FIG. 2 in this state, as a result of many sample experiments, the surface destruction of the paper 1 follows the locus of 7 and reliably stops at the cut position of 5. In this case, the coated paper of the paper 1 is peeled. This is because when the paper fiber component such as high-quality paper appears on the surface, a deeper cut is required to stop the breakage with the cut. Still further, in order to control the fracture, the notch 5 in FIG.
It is effective to put it on the side opposite to the pressure-sensitive adhesive 3 and also to put it on the position of the pressure-sensitive adhesive 3. Further, in FIG. 2, a cut 5
Is also effective. In any case, it is desirable that the design of the cut is appropriately made depending on the shape of the opening portion of the letter and the manner of opening, the manner of applying the pressure-sensitive adhesive, and the material mainly on the state of the paper fiber of the paper.

[0006]

As described above, by treating the seal opening portion with a notch for preventing destruction, it is possible to minimize the destruction of the seal opening portion by manual opening and to easily open the envelope. Can be provided. This makes it possible for the sender to give consideration when applied to mail envelopes. Further, since the cut of the present invention can intentionally induce breakage of the paper when opened, it is well suited to applications requiring confidentiality such as falsification prevention.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the arrangement of a pressure-sensitive adhesive and a cut in a sealed letter unsealing portion before sealing adhesion.

FIG. 2 is an explanatory cross-sectional view showing a positional relationship between members of an unsealing portion of a sealed letter.

FIG. 3 is an explanatory cross-sectional view showing a situation of breaking and cutting when a sealed letter is opened.

[Explanation of symbols]

 1... Paper forming a sealed letter 2... Paper forming a sealed letter opposed to 1 3... Pressure-sensitive adhesive for sealing the opening of the sealed letter 4. Gap ... 5 ... cut to stop breaking at opening 6 ... ... direction of applying force at opening 7 ... assumed line of breaking at opening 8 ... thickness of paper 1 9 ... Depth of the cut 5 formed in the paper 1 A.... Represents the cutting position of the cross section in FIG. 2 and FIG. 3 in FIG.

Claims (1)

[Claims] 1. A rectangular envelope is coated with a pressure-sensitive adhesive on one or more overlapping portions using high-quality paper or coated paper ranging from 81 g per square meter to 162 g per square meter. At this time, the distance from the pressure-sensitive adhesive is 0.5 mm to 10 m in a straight line or a curve along all or a part of the edge of the bonding portion of the joint with the pressure-sensitive adhesive.
m, with a gap of not more than 1/2 of the thickness of the paper being cut and bonded on both or one of the bonding surfaces of the stacked papers. And manufacturing method.