JPH02205558A - Foamed sheet make square bottom bag and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a number of inexpensive square bottom bags with stable sizes and forms, by providing a joint line of a sheet, starting from the middle of respective opposite sides of an opening and separating to be two lines at the point of a half depth from the bottom to reach four corners of the bottom. CONSTITUTION:Sizes of a square bottom bag are made as follows: folded depth of a gazette 7 = b/2, where a shorter side of the bottom 3 = b, a triangle 11 separated by seal/cut 4 forms a right isosceles triangle and the cut depth = b/2 and hence, the cut width = b, and moreover a+b = constant distance, where a longer side of the bottom 3 = a, the length of seal/cut = (c-b/2), where the height of the square bottom bag = c. If the form of the triangle separated by seal/cut 4 is changed, several forms of square bottom bags are obtained. A composite sheet is folded by a half 6 to form the gazette 7 in the direction to recess the half-folded line and a heat resistant plate is inserted into the gazette and further the triangle is drawn out of seal/cut every certain distance and by seal/cut 4 on the line crossing the half-folded line, passing the top of the triangle, in order to make the square bottom bag.

Description

[Detailed description of the invention] (Industrial field of application) Lightweight, easy-to-understand, robust, heat-retaining, etc. used for home delivery, book transport, cold bags, shopping bags, etc., which require low security. The present invention relates to a square bottom bag.

(Prior Art) As a conventional technique for producing square bottom bags, the ``two triangular bottom gusset method'' and the ``horizontal gusset method'' are known. It is also conceivable to repurpose the sheet-fed method for manufacturing square-bottomed paper bags, but there are no examples of this being implemented.

The shape of the square bottom bag is shown in Fig. 2, and the manufacturing method is shown in Fig. 6.
Fold the original fabric in half (6) and seal/cut at regular intervals (4
)do. After sealing/cutting (4) at regular intervals, 90
"Rotate and make a new fold so that the seal/cut line (4) becomes the center line. At the same time, fold it inward using an origami motion (lO) to form a triangle. Next, fold a part of the apex side of the triangle. Seal/cut (4) and separate.

In the horizontal gusset method, the shape of the square bottom bag is shown in Fig. 3, and the manufacturing method is shown in Fig. 7. In Fig. 7, the original fabric is folded in half (6
), seal (8) to form a tube, and fold in gussets (7) from both sides.

The tube-like product with both sides folded inward is sealed at regular intervals (8) and then cut (11) to separate it. The sealed/cut product is pressed and expanded as shown in FIG. 3 to form a square bottom bag having overlapping portions (9) at both ends of the bottom surface (3).

For the single-wafer method, the shape of the square bottom bag is shown in Figure 4, and the developed view is shown in Figure 8. In Fig. 8, fold it back so that the solid line 51 becomes the outgoing line and the dashed-dotted line 52 becomes the valley line, forming a square bottom bag shape as shown in Fig. 4, and each overlapping part (9) is placed in order. For example, if it is a square bottom bag made of paper, it is sealed (8) with glue to form an overlapping part (9) to form a square bottom bag.

(Problems to be Solved by the Invention) As shown in Figure 2, in the "degree two triangle bottom gusset method", the part where the bottom surface (3) contacts the side surface (2) is side sealed (4). ing. When storing and transporting items in a square bottom bag, the load of the item is mainly applied to the bottom (3), so the bottom (3) and the boundary between the bottom (3) and the sides (2) have the highest load capacity. and buffering properties are required. However, since the boundary between the bottom and side surfaces is sealed (4), there is a problem in that the boundary, which requires the most load bearing capacity, is more likely to break. Furthermore, if the boundary area is sealed (8), the air bubble sheet (21) will become soaked with air bubbles, so the area that requires the most cushioning properties will instead become insulated.
There was also the problem that the weight was poor. Furthermore, as shown in FIG. 6, there is a problem in that the manual origami operation (10) step is difficult to mechanize. Japanese Patent Application Publication No. 1974-. 46
No. 673 and Japanese Patent Publication No. 59-30541 are inventions that attempt to mechanize this, but it cannot be denied that the devices become complicated. In addition, the folded square bottom bag has a large proportion of 4-layered parts. Since bubble sheets are several orders of magnitude thick, they are very different from paper or film, and they also have the problem of being bulky when overlapped.

“Horizontal gazette method” (for example, JP-A-60-172656
Publication No. 172657/1983, Japanese Patent Application Laid-Open No. 1982-172657
100441), there was a problem in that an overlapping portion (9) was formed during use, as shown in FIG. 3d. Furthermore, as shown in FIG. 7, there is a problem in that it is difficult to align and seal the edges of the original fabric continuously (8).

The "single wafer method" (for example, Japanese Unexamined Patent Publication No. 181632/1983) has a problem in that there are many overlapping parts (9) as shown in Fig. 4.The overlapping parts (9°) °
However, since the typical raw material for cellular sheets is non-polar polyethylene, there is a problem in that it is difficult to adhere the overlapping portions (9) of cellular sheets or composite sheets. Furthermore, since the overlapping portion (9) of the bubble sheets is undesirably bulky, there is a problem in that one of the bubbles must be crushed. Even in the production of square bottom bags made of paper, which is relatively easy to automate, some manufacturers still apply the process by hand7. It must be said that automation is even more difficult when manufacturing.

(Means for solving problems) The present invention will be explained using FIGS. 1 and 5.

Although FIG. 5 illustrates a method in which the bubble sheet (21) is used alone and the pack film (23) is placed on the outside, the present invention is not limited to this. As illustrated in the examples, even if the cap film (22) is used on the outside, the bubble sheet (21) with the liner film (24) attached to the cap film and (22) side opposite to the pack film (23) can be used. ) (FIG. 11a), or a composite sheet of these bubble sheets (21) and another base material (25) (FIG. 11b) may be used. Also, foamed polyethylene may be used instead of the cell sheet or other base material.

The shape and dimensions of the square bottom bag of the present invention shown in FIG. The manufacturing method will be explained in further detail.

In Fig. 5a, depth of gusset (7) folding = b/2
, Seal/Cut (4) and Separate (11) The triangle is a right isosceles triangle, and the cut depth is b/2, so the cut width is b. The constant interval=a+b, and the length to be sealed/cut is (c-b/2). Seal/Cut (4) and Separate (11) By changing the angle of the triangular shape or changing it to a smooth curve instead of a straight line, you can obtain a variety of modified square bottom bags such as boat bottom shapes and round bottoms.

The method for sealing/cutting (4) is, for example, the impulse melting method in which the heater wire is energized for a short time.
``Energy beam fusing sealing method'' using a laser beam, etc. There is a method in which a sealing (8) device is provided before and after each cutting (11) device. The method for sealing (8) is heat sealing using contact heat transfer.
There are "high frequency seals" using dielectric heating, "ultrasonic seals" using frictional heat generation, "adhesion" using intermolecular forces, and "sewing" using thread. In special cases where the cellular sheet or the composite sheet of which the cellular sheet constitutes a part has electrical conductivity and magnetic hysteresis, induction heating sealing is also possible. Cutting methods (11) include Pasen new method, tearing ``midair cutting method''
There are three types: ゛ and “crash method°”. "°Sen new methods°" include the guillotine method using two straight blades, the method using a driving rotary blade and a driven rotary blade, and the method using driving rotary blades for both the upper and lower blades. The aerial cutting method using bow splitting includes a method using two straight blades, a method using two driven rotary blades, etc.

(Function) As shown in Fig. 5a, the cell sheet or the composite sheet of which the cell sheet constitutes a part is folded in half (6), and a gusset (7) is formed in the direction in which the above-mentioned half-fold line is invaginated. , With the heat-resistant plate inserted into the gusset, seal/cut triangles at regular intervals and remove them, and then seal/cut (
4) Then, form a square bottom bag as shown in Figure 1a.

(Example) A bubble sheet (21) consisting of a cap film (22) having a large number of protrusions with a height of 3 to 5 and a diameter of 7 to 15+U and a flat pack film (23). ), with the pack film (23) on the outside, the long side a of the bottom shown in Figure 1a = 30 to 45C11, and the short side b of the bottom = 10 to 2
0c11. A square bottom bag with a height C of 25 to 50 cm was experimentally produced. It was a square bottom bag that was lightweight, robust, l1ffi and heat retaining.

A bubble sheet (21) having the same shape as in Example 1 was used with the cap film (22) on the outside.

By sealing/cutting (4) and eliminating the isosceles triangle whose apex angle is 120@,
A modified square bottom bag as shown in Fig. 9 was prototyped. Although the bag was approximately the same as Example 1 in terms of dimensions, it had a different shape in the shape of a ship's bottom, and was a square bottom bag with bubble projections on the outer surface.

11■U Same height as Example 1 = 3~5 m11, diameter = 7~15
The bubble sheet (21) shown in Fig. 10 is made by pasting a plain pack film (23) and a clear liner film (24) on both sides of a cap film (22) having a large number of convex portions. A square bottom bag having the same shape and dimensions as in Example 1 was manufactured by using the following.

Pack film ( 23) on the outside, and then use the pack film (
23) On the outside, basis weight = 70 to 150 g/rr? pasted with craft paper.

Using the composite sheet, am30-45c11. b
~10-20 am, c = 25-50 cm
We prototyped a square bottom bag.

A square bottom bag was experimentally produced in the same manner as in Example 4. However, weight =
Instead of using 70 to 150 g/rrf kraft paper, a single-sided corrugated cardboard sheet with a pile height of 1 to 5 was used.

A square bottom bag was prototyped in the same manner as in Example 4. However, instead of using kraft paper with mesh f = 70 to 150 g/rd, the same bubble sheet (21) as in Example 4 was used. A composite sheet was used in which foamed polyethylene with a thickness of 0.3 to 4I+111 was adhered to the inside of the case.

A square bottom bag was experimentally produced in the same manner as in Example 4. However, instead of using craft pressure with mesh size f = 70 to 150 g/r + f, on the outside of the bubble sheet (21) similar to Example 4,
A composite sheet with a so-called flat yarn cloth attached thereto, which is obtained by plain weaving uniaxially stretched polyethylene strings, was used. The robustness was further improved compared to Example 4.

Actual M A square bottom bag was experimentally produced in the same manner as in Example 4. However, weight =
Instead of using 7Q~150g/rrf kraft paper, on the outside of the bubble sheet (21) similar to Example 4, 1
Rolled polyethylene sheet.

A composite sheet was used, in which multiple sheets were laminated with different stretching directions and pasted together. It had almost the same robustness as the implementation fN7.

``Sou 11 Sails'' - A smooth pack film and a smooth liner film are pasted on both sides of the cap film (22), which has a large number of protrusions with a height of 2 to 5 II11 and a diameter of 5 to 10 degrees, to create air bubbles. A sheet (21) was formed.

CPP deposited with aluminum on the outside of the bubble sheet (21)
(casting polypropylene) using a composite sheet pasted, a = 30 ~ 45 c + s
, b = 10~20 cm, c = 25~
I made a prototype of a 50c11 square bottom bag.

(Effects) As explained above, the method for manufacturing the square bottom bag of the present invention does not involve any process that is difficult to mechanize or automate, unlike the prior art "degree two triangle bottom gusset method", so manual labor is required. The square bottom bags can be continuously manufactured using a manufacturing device that does not require a manufacturing method. Therefore, square bottom bags with stable dimensions and shapes can be provided in large quantities at low cost.

The manufacturing process of the present invention consists of simple steps centered on sealing/cutting, and square bottom bags can be made from various materials by selecting the sealing/cutting means.

In the prior art, in both the "two-triangular and bottom gusset method'° horizontal gusset method'° and the single wafer method", a seal line exists on the bottom surface or at the boundary between the bottom surface and the side surface,
The sealed portion is soaked with air bubbles and lacks 41 rji properties, and the sealed portion is easy to tear and has poor load bearing capacity.In contrast, the square bottom bag of the present invention has seal/cut lines limited to only the sides. Because of this, it retains its sturdiness and load-bearing properties.

The square bottom bag of the prior art horizontal gusset method produces an overlapping part on the bottom surface when in use, making the stored items unstable, but with the square bottom bag of the present invention, the stored items are stable. .

The boat-shaped square bottom bag shown in FIG. 9 explained in Example 2, the first
A square bottom bag with a round bottom as shown in FIG.

The present invention has been described in detail in comparison with the prior art, but
Table 1 shows this in a table.

Table 1

[Brief explanation of the drawing]

Figure 1 shows the square bottom bag of the present invention, Figure 1 a, b, c, d.
Figures 2, 3 and 4 are perspective views, front, side, and bottom views, respectively, of the prior art two-triangle bottom gusset method;
This is a square bottom bag made by the horizontal gusset method or the single wafer method, and each of a, b, c, and d in Fig. 2.3.4 is a perspective view, the front, side, and bottom, and Fig. 5 a is the square bottom of the present invention. 5 shows a cross-sectional view taken along the line A-A in FIG. Figures 9 and 10 show one embodiment of the square bottom bag of the present invention, Figures 9 and 10 a are folded state diagrams, and Figures 9 and 10 are A of Figures 9 and 10 a. -A cross-sectional view, Figure 9.10 C is a perspective view of the state of use, Figure 11
Figures a and b show one example of a cellular sheet and a composite sheet. l is the front, 2 is the side, 3 is the bottom, 4 is the seal/cut line, 5 is the folding line, 51 is the outgoing line shown as a solid line, 52 is the valley line shown as a dashed line, 6 is folded in half, 7 is the gazette, 8 is a sticker, 9
is the overlapping part, 10 is the origami movement, 11 is the cut, 1
2 is the folding line, 13 is the valley line when folded (not folded when in use), 21 is the bubble sheet, 22 is the cap film, 23 is the pack film, 24 is the liner film, 25 is the base material of the pond, a is the bottom surface , b is the short side of the bottom, and C is the height of the square bottom bag.

Claims (2)

[Claims] (1) In a square bottom bag in which five sides of a rectangular parallelepiped are formed by a cell sheet or a composite sheet of which a cell sheet constitutes a part, the seam line of the sheet is the midpoint of each of the two opposing sides. 2 points each at a distance of 1/2 of the base length from the base.
A square bottom bag that branches into books and reaches four vertices on the bottom. (2) Fold the cell sheet or a composite sheet of which the cell sheet is a part in half, form a gusset in the direction of the above-mentioned half-fold line, and insert the heat-resistant plate into the gusset at regular intervals. Claim 1 characterized in that, while sealing/cutting and eliminating the triangle, sealing/cutting is performed on a line passing through the vertex of the triangle and perpendicular to the half-fold line.
The manufacturing method of the square bottom bag described.