JPH0624787B2 - Square bottom container manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a square bottom bag called a gusset bag or the like having a gusset on both sides and a square bottom shape, and milk, juice and the like. The present invention also relates to a method of manufacturing a carton container containing a liquid, which also has a rectangular bottom.

[Prior Art] FIGS. 13 and 14 show what is called a conventional gusset bag.
The manufacturing method of FIG. 13 is one in which V-shaped folds are inserted from both sides of a material formed into a cylindrical shape by back-adhesion, etc., and flatly folded in this state, and the bottom is sealed in a horizontal straight line.
The manufacturing method shown in the figure is such that the bottom paper is folded from each side, and a square backing paper is pasted on this.

FIG. 15 shows a carton container containing milk and juice. The carton container has a structure in which it is folded on a mandrel by a bottom seal machine to form a bottom and the weight surface is heat-sealed.

[Problems of the prior art] In the above-mentioned prior art, the gusset bag has a characteristic that it can be manufactured relatively easily, but the bag is made from a material having no heat-sealing property such as paper or aluminum foil. In this case, a heat-sealable plastic film such as polyethylene which is melted at a low melting point must be laminated on the inner surface. Therefore, the cost is high, and the laminate material or adhesive may come to the inner surface and dissolve in the contents. Further, when a square bottom bag is made of a material that does not have a heat-sealing property as shown in FIG. 14, the bag-making process becomes complicated and there is a problem in the sealing property of the bottom. It cannot contain liquid.

Next, in the case of the square bottom container as shown in FIGS. 13, 14 and 15, there is a problem that the seating is bad because there is an overlap at the bottom, folding back and sealing edges come.

Next, in the case of the carton container as shown in FIG. 5, there is a problem that the bottom sealing process is increased by one, productivity is poor, the machine is complicated, and the production cost is high.

INDUSTRIAL APPLICABILITY The present invention can easily manufacture a square bottom bag with a material having no heat-sealing property such as paper and aluminum foil, and has excellent sealing property and a corner with no overlap or a sealing edge. The aim is to propose a method of manufacturing a bottom container.

[Means for Solving the Problems] The present invention proposes the following manufacturing method as means for solving the above problems.

Bending both edges of the sheet-shaped container material to the same surface side and abutting each other to form a flat cylinder, a step of applying an adhesive on the outside of the abutted edges, A step of forming an inverted V-shaped fold from behind to form the lower part of the cylindrical body in a W shape, a step of adhering the adhesive-coated portion of the cylindrical shape of the W shape from the outside, A method of manufacturing a square-bottomed container.

In the above manufacturing method, the adhesive is not particularly limited, and an adhesive suitable for the material such as paper or aluminum foil is selected.
Then, this adhesive may be applied after bending both edges of the sheet-shaped container material to the same side, or may be applied in advance before such processing.

Alternatively, instead of the adhesive, a heat-sealable plastic film such as polyethylene may be adhered only for the adhesive margin, and the film may be heat-sealed using a heat-seal bar for adhesion.

Next, a notch of approximately 90 ° is formed in each of the two edges of the sheet-shaped container material so as to face each other, and an adhesive or heat seal layer is provided from the outside of both edges of the sheet-shaped container material along the edges of the notch. Inverse V for a flat cylinder formed continuously
The letter-shaped folding may be performed in the middle of this notch, and the W-shaped folded portions may be respectively performed at the center of the notch, so that the triangular fold protruding inside the container may be eliminated and the appearance may be adjusted.

[Embodiment] Both edges 2 and 2'of a sheet-shaped or film-shaped container material 1 as shown in FIG. 1 are bent to the same plane side, and as shown in FIG. Form.

Next, as shown in FIG. 3, adhesives 4 and 4'are applied along the outer sides of the abutted edges 2 and 2 '.

Next, as shown in FIGS. 4 and 5, an inverted V-shaped fold 5 is inserted from behind both edges 4, 4'of the cylindrical body 3 to form the lower portion of the cylindrical body 3 into a W-shape.

Next, as shown in FIG. 6, the surfaces of the cylindrical body 3 to which the adhesives 4 and 4'are applied are pressure-contacted from the outside to adhere them.

The bag made as described above is expanded in the direction of the arrow in FIG. When the bag is expanded in this way, as shown in FIG. 8, the inverted V-shaped fold 5 portion is pulled up in the direction of the arrow on the inner bottom of the bag, and the bottom is opened in a quadrangle. FIG. 9 shows a state in which the folded-in portion 5 of the inner bottom is vertically erected and along the side wall, and FIG. 10 shows the entire shape of the bag.

As is clear from FIGS. 8 and 9, in FIG. 11, the parts (folds) folded in the inverted V shape remain on both sides of the inner bottom, and this damages the appearance. Therefore, remove this part as much as possible. In order to arrange the appearance, first, at the symmetrical positions on both sides of the inverted V-shaped fold 5 in the cylindrical body 3, cuts 6, 6 ′, 7, 7 of approximately 90 ° are made at the abutting portions of both edges 2, 2 ′. ′
When you put in and fold the bottom into a W shape, make this notch 6,
The central lines P, P'of 6 ', 7, 7'are set so as to be the lower edges (L, L'in FIG. 4) of both sides. In this way, when the bottom is opened in FIGS. 8 and 9,
As shown in FIG. 12, a triangular portion h shown by a chain line,
Since h'is lost, there is no obstacle in the inner bottom, and it is refreshing.

[Effect of the present invention] As described above, the present invention bends both edges of a sheet-shaped container material to the same plane side and abuts each other, and forms an adhesive or heat seal layer along the outside of the abutted edges. Then, by folding this into a W-shape at the bottom portion and crimping or heat-sealing from both sides, it is possible to easily make a corner bottom bag with a gusset or a carton container having a corner bottom.

Therefore, the manufacturing cost of the square-bottomed container is reduced, and a material having no heat-sealing property such as paper and aluminum foil can be used alone to form the square-bottomed container.

Next, in the case of a conventional square bottom container, a film having heat-sealing property was laminated on the inner surface of the container, but the present invention is only a portion to be adhered, and it is also an adhesive or heat on the outer surface of the container material. Since only the sealing layer needs to be formed,
The contents are not directly touched by the adhesive or the laminated film and are not adversely affected.

Next, the bottom surface of the finished container becomes one smooth surface and there is no overlapping part, so it is very comfortable to sit on.

[Brief description of drawings]

FIG. 1 is a development view of a sheet-shaped container material, and FIG. 2 is a plan view in which the container material is bent and both edges thereof are butted.
FIG. 3 is a plan view of a state in which an adhesive is applied to the outside along both edges, and FIG. 4 is a W-shaped cylinder formed by inserting an inverted V-shaped fold into the portion to be the bottom. Perspective view of the state,
Fig. 5 is an enlarged cross-sectional view of the center of the bottom, Fig. 6 is a cross-sectional view of the lower part in which the adhesive parts are stuck together, and Fig. 7 is a plan view of the bag with the bag opened after bag making, FIG. 8 is a partially cutaway perspective view of the process in which the inner bottom is formed into a quadrangle, and FIG. 9 is a partially cutaway perspective view showing the inner bottom of the bag which is completely opened at the corner bottom.
FIG. 11 is a perspective view showing the overall shape of a bag manufactured according to the present invention, and FIG. 11 is a plan view of a cylindrical body when a cut is made to reduce the portion protruding into the inner bottom as much as possible. The figure is a partially cutaway perspective view showing the inner bottom when the bag is made using the cylindrical body shown in FIG. 11, FIG. 13 is a perspective view showing the bottom of the conventional gusset bag, and FIG. 14 is the conventional bottom. FIG. 15 is a perspective view of a square bottom bag made by pasting, and FIG. 15 is a perspective view showing a bottom portion of a conventional carton container. 1 ... Container material 2, 2 '... Both edges 3 ... Cylindrical body 4, 4' ... Adhesive 5 ... Folding, 6, 6 '... Notch 7, 7' ... Notch

Claims (3)

[Claims] 1. A step of forming a flat cylindrical body by bending both edges of a sheet-shaped container material to the same side and abutting each other, a step of applying an adhesive to the outside of the abutting both edges, said cylinder A step of forming an inverted V-shaped fold from behind both edges of the body to form a lower portion of the cylindrical body in a W shape, and pressing the adhesive-coated portion of the W-shaped cylindrical body from the outside. A method of manufacturing a square bottom container, which comprises the steps of: 2. A heat seal layer is formed on the outer sides of the abutted edges in place of an adhesive, and the heat seal bar is pressed to weld the heat seal layers to each other.
A method for manufacturing the described square bottom container. 3. A sheet-like container material is formed with notches of approximately 90 ° facing each other at two edges of the sheet-like container material, and an adhesive or heat-sealing layer is provided from the outside of both edges of the sheet-like container material to the edges of the notches. The corner bottom according to claim (1), which is formed continuously along with the flat cylindrical body, and performs an inverted V-shaped fold in the middle of the cut, and a W-shaped folded portion at the center of the cut. Container manufacturing method.