JPS6116991Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a paper container (called a seal sack or holding carton) that is made by punching, cutting, bending, and gluing paperboard, and then sealing the contents with adhesive after storing the contents. The purpose is to obtain a folding box that does not cause leakage of contents.

This type of folding box is made from a flat state made by punching and cutting paperboard into a shape suitable for forming a container, or from a folded flat state with the side edges glued together. Just before filling the contents, the folding box is shaped into a cube, and the bottom panel After adhering the flaps, the contents are filled, and the upper panel and flaps are folded and adhered to form a packaging box.The adhesion in this step is performed using a water-based adhesive such as polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, Panels and flaps are usually bonded by applying an emulsion type adhesive such as vinyl acetate or acrylic copolymer.

The above-mentioned folding box is used for direct filling and packaging of contents.
This is usually done by an automatic machine and is widely used for powder packaging such as powdered detergents and powdered pastes, but after the bottom is bonded, the powder is filled and the top is bonded, so pressure is applied after applying the water-based adhesive. In the flap part of the top part where no adhesive is applied, moisture absorption curls in the flap part, making it difficult to achieve a sufficient adhesive seal. This was the cause of the leakage accident.

The present invention solves the above problems.

Hereinafter, in embodiments shown in the drawings, the above-mentioned problems as well as the structure and operation of the present invention will be clarified.

Fig. 1 shows the punched and cut shape of a paperboard in the case of normal folding box manufacturing, that is, a developed view of a folding box. 1 and 1a are upper flaps, 2 and 2a are upper panels, 3 and 3a are lower flaps, and 4 and 4a are In the lower panel, 5 is a side gluing margin, 6 is a fold line (indicated by a thin line), and 7 is a powder shaker opening forming part, and cutting edges are provided in the direction of each vertical fold line, respectively, as shown by thick lines. FIG. 2 shows a state in which the one shown in FIG. 1 is folded, the side gluing margins 5 are glued to the flap sides 1a and 3a, and the flap is folded flat.

FIG. 3 is a perspective view showing the packaging process of forming a folding box, filling with powder, and gluing the top part, in which a indicates the first,
From the state shown in Figure 2, make it into a three-dimensional shape and attach the lower flaps 3, 3.
After applying adhesive to side a and the back of lower panels 4 and 4a,
Figure b shows the state in which the bottom is formed by folding, after filling the content powder M, the upper flaps 1 and 1a are folded inward and the upper panels 2 and 2a are folded outward, and adhesive is applied to the upper surface. The state of the stage to perform, c, is the upper panel 2 by folding the upper panels 2a and 2 in this order.
a to the upper flaps 1, 1a on its lower surface;
This figure shows the state in which the packaging is completed, with the upper surface being adhered to the upper panel 2 to form a sealed top.

In the above process, the bottom and top flaps,
If the panel is properly and reliably bonded, no problem will occur, but it often tends to cause flaps at the top and poor adhesion of the panel. This is because the bottom flap and panel are normally located on the base plate, and the weight of the powder content maintains the adhesive surface in a compressed state, resulting in a sufficiently strong bond. Upper flap 1, 1a, upper panel 2, 2
In case a, the flap 1, which has a small bonding area, is simply folded and press-welded without contacting the surface of the filled content powder M, and is bonded only by the adhesive force of the adhesive. 1a tends to curl and peel as shown in the fourth figure due to expansion due to moisture absorption of the adhesive, resulting in an insufficient adhesive state.

This curl of the flap is caused by the fact that the flap 1a is more rigid than the flap 1a, which is made of polymerized side gluing allowance 5.
This is even more serious, as shown in the cross section of Fig. 4, where the adhesive seal is hardly sealed, and the internal pressure of the powder M during handling of the package and the external force during handling cause the flap 1 and panel 2a to This may cause the adhesive to peel off, leading to accidents such as powder leakage or infiltration of outside air moisture.

In view of this point, the present invention has the upper flaps 1, 1a
Particularly, a non-hygroscopic coating film 10, for example, offset printing, is applied to a part of the adhesive surface of the flap 1 which is not adhered in the side gluing margin 5, for example, the surface surrounded by the dashed line in FIG.
An overprint varnish layer is provided by silk screen printing or gravure printing as shown in Figure 5 to suppress the penetration of adhesive moisture into the flap 1, thereby preventing the flap 1 from curling and improving the upper panel 2a. This prevents the adhesive area from decreasing and thereby maintains the adhesive strength of the area.

The coating area and shape of the non-hygroscopic coating film 10 depend on the paper quality,
It is determined as appropriate depending on the type of adhesive, etc., but it is necessary to form it in a range close to the folded edge from the tip of flap 1 with at least 1/2 of the area of flap 1 in order to obtain the curl prevention effect. The non-hygroscopic coating film 10 is formed by printing a conventional synthetic resin paint such as polyamide, vinyl chloride, acrylic, resin, nitrocellulose, or phenol alkyd resin as shown in the figure.

The present invention has the above-mentioned structure, and has practical advantages in that a folding box can be obtained by an extremely simple means in which the top part can be completely sealed with a flap that prevents moisture absorption curl due to the applied adhesive moisture. The effect is excellent.

[Brief explanation of the drawing]

1 to 4 illustrate conventional folding boxes, in which FIG. 1 is a plan view corresponding to a developed view of the folding box cut by punching, FIG. 2 is a plan view of the folded box with the sides glued, and FIG. The figure is a perspective view showing each process of folding box formation, powder filling, and top adhesive sealing. Figure 4 is a vertical cross-sectional view of one corner of the upper part. Figure 5 is a schematic diagram corresponding to Figure 3b above in the embodiment of the present invention. FIG. 1, 1'...Top flap, 2, 2a...Top panel, 3, 3a...Lower flap, 5...Side gluing allowance, 6...Fold line, 7...Drawing opening forming part, 10
...Non-hygroscopic coating film, 11...Top flap, 12
...Top panel.

Claims (1)

[Scope of utility model registration request] In paperboard folding boxes that are sealed with a water-based adhesive after containing powder, a non-hygroscopic adhesive is applied to the adhesive surface of the upper flap in an area of 1/2 or more of that surface, from the tip of the flap to the area close to the folded edge. A folding box characterized by having a coating film.