JPH01202429A - Square bag and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a square bag, which has no joint at the boundary portion between a square bottom and each side part, by a structure wherein first sealing parts, the shape of each of which is an angle form with its lower ends at both corner parts on a bottom side, and second sealing parts, each of which is formed upward in a straight line from the apex of the first sealing part, are equipped on sides, which oppose to each other. CONSTITUTION:Thermoplastic synthetic resin foamed sheets S are drawn out of raw sheet feed rolls 12. One end (b) of one sheet and that of the other sheet are welded together with a side sealer 14. A V-shaped tucked part (e) is formed with supporting members 16 by pressing the end (b) inward with a tucking member 15. The predetermined positions of the sheets S are cut off and welded with sealing cutters 20 so as to obtain a square bag K. The square bag R is carried by means of a carriage conveyer 23 to a product pan 24. Under the state that the manufactured square bag K is spread, triangular sides 2, each of which is produced by the V-shaped part 20' of the sealing cutter 20, are provided at both ends of a square bottom 3 under the seamless and continuous state with respect to the square bottom 3. Second sealing parts 5 presenting themselves at the vertical middles of respective sides 2 and 2 are produced by the straight-line part 20'' of the sealing cutter 20. Angle-shaped first sealing parts 4 are produced by the V-shaped part 20'. A third sealing part 6 running from the triangular sides 2' to the square bottom 3 is produced with the side sealer 14.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a square bottom bag having a gusset on the side and a method for manufacturing the same. This is a method of manufacturing a square bottom bag using an automatic device or the like from a thermoplastic synthetic resin foam material which is formed into a sheet shape with one end connected.

<Prior art> Various shapes of bags for storing items have been provided in the past, but square bottom bags with gussets on both sides of the bag to increase the storage capacity have little utility value. Due to its high price, it is used for various purposes. In particular, when storing raw or easily damaged items, a sheet of synthetic resin foam material is used to make the bag resistant to water and have a certain degree of strength, and to protect the stored items. Square bottom bags are provided.

Such a square bottom bag made of synthetic resin foam material is made of, for example, a foamed polyethylene sheet, and as shown in FIG. (51a) is provided, and a square bottom (51a) is provided.
2) is provided with a welded part (52a) formed in a straight line connecting the lower ends of the welded parts (51a) (51a) formed on the side parts (51) (51), and this corner The bottom (52) is joined to the lower ends of the side parts (51) (51) via welded parts (53) (53).

On the other hand, the conventional method for manufacturing square-bottomed bags like the one described above from foamed polyethylene sheets is to overlap two foamed polyethylene sheets and weld the periphery to form a glove. The piece is placed over a deformable member for folding formed into a pantograph shape, and by rotating the deformable member, it is once expanded into a square bottom shape and then folded in the middle for the square bottom, and then the half-folded part is A square bottom bag was formed by inserting a fluororesin-treated intermediate material and removing the excess ears protruding from the bottom by welding and sealing with a heat-sealing tool pressed from the outside. -30
(See Publication No. 541).

<Problem to be solved by the invention> However, the above-mentioned conventional square bottom bag has a square bottom (52).
In other words, the square base (52) and the side parts (51)
Welded parts (53) (53) are formed at the bent part where the material is connected to the container, so these welded parts have low strength and easily peel off when objects are stored. Met.

In addition, in the conventional method of manufacturing a square-soled bag, after forming a flat bag which is an alternate product, the flat bag is attached to the above-mentioned forming apparatus to manufacture a square-soled bag, so that the step of manufacturing the glove It is difficult to connect the process of forming the square-bottomed bag and the process of forming the square-bottomed bag in a series of work lines, and it has been impossible to manufacture the square-bottomed bag by assembly line operations. For this reason, in order to manufacture such square bottom bags, it is necessary to install individual manufacturing equipment corresponding to each work process, which requires additional equipment for receiving and receiving semi-finished products, which increases equipment costs. As the cost increases, production efficiency is poor, which poses a problem in that it becomes an obstacle to improving product costs.

The present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to provide a square bottom bag that does not have a joint at the boundary between the square bottom and the side part. A second object of the present invention is to provide a method for manufacturing a square-bottomed bag in which the process from material to product formation can be carried out in a series of operations.

Means for Solving the Problems> In order to achieve the first object, the square bottom bag of the present invention has a mountain-shaped first seal having two lower ends at both corners on the bottom side, on opposing sides. and a second seal part formed linearly upward from the apex of the first seal part at the side part, and the bottom part is formed with respect to the triangular side part located below the first seal part. In order to achieve the second object, the manufacturing method of the present invention includes a long piece made of a thermoplastic synthetic resin foam material. The raw material is formed into two overlapping sheets with one side end connected, and while running in the longitudinal direction, the end is cut into 1/1/2 of the vertical width of the square bottom. After folding it into a V-shape to a depth of 2, it is cut and welded at predetermined intervals in the direction perpendicular to the longitudinal direction, and the intersection point between the welded end face and the deep part of the folded part is the end. It is characterized by forming a square bottom by cutting and welding both ends of the folding side diagonally so that the bottom ends are as follows.

Function> According to the square bottom bag described above, the bottom is seamlessly formed with the triangular side by the first seal portion formed in the shape of a mountain on the side, so that the side No seam is formed at the boundary between the bottom part and the bottom part, and damage at this point 8 can be prevented.

In addition, this square bottom bag can be manufactured by making cuts in a long cylindrical raw material made of thermoplastic synthetic resin foam, or by stacking two sheets together and welding one end. While transporting a long raw material obtained by folding a single sheet in half, a 7-shaped fold is formed at the continuous side edge, so the overlapped part can be used as a side part as a bag. In addition, the folded portion can form a square bottom portion and a part of the side portion. Then, the material is cut and welded at predetermined intervals in a direction perpendicular to the longitudinal direction of the original fabric, and the folded side is cut and welded so that the intersection point between the welded end face and the deep part of the folded part becomes the end. After both ends are cut and welded diagonally, and then expanded inward from the open side, which is the other end in the conveying direction, a square bottom can be formed with the folded portion, and a square bottom can be formed on this square bottom. It is possible to manufacture a square bottom bag in which a part of the side part is formed seamlessly and continuously.

<Example> First, a square bottom bag as an example of the present invention will be described.

FIG. 1 is a perspective view of the square bottom bag, and FIG. 2 is a perspective view of the square bottom bag as seen from the bottom side.

This square bottom bag has opposite side parts (1) (1) and side parts (2) (2) formed in the same shape, and these side parts (1) (1) (2) (2). A square bottom (3) is provided at the lower end. and opposing sides (2) (2)
has a first seal part (4) in the shape of a mountain with lower ends at both corners < a on the square base (3) side, and the side part (2).
) At the vertical center of (2), the first seal part (4
) is formed linearly upward from the apex of the second seal part ( ).
5), and the square bottom (3) is provided with the first seal portion (4).
) Triangular side portion (2') at the lower position (2') is formed in a continuous state without forming a seam.

Next, a schematic structure of a manufacturing apparatus for manufacturing the above-described square bottom bag will be described below with reference to the drawings.

FIG. 3 is a schematic side view of the manufacturing apparatus, FIG. 4 is a schematic plan view of the apparatus, and FIG. 5 is a perspective view of a square bottom bag manufactured by the manufacturing apparatus.

This device consists of two raw fabric supply rolls (12) each wound with a thermoplastic synthetic resin foam sheet (S), and two synthetic resin foam sheets (S) fed out from the raw fabric supply rolls (12). ) is conveyed in an overlapping state, and one end (b) of two synthetic resin foam sheets (S) is conveyed downstream of the first feed roller (13). A side sealer (14) configured by an impulse heater or a rotor heater, for example
and the joined end of the synthetic resin foam sheet (S) (
b) is folded inward in a 7-shape with a predetermined depth, a disc-shaped folding member (
15) and the support member (16), which is arranged opposite to each other in a position sandwiching the disc part of the folding member (15) and is installed in an oblique state with the downstream side facing inward, and the folded part are overlapped. Press them together, and then press the step roller (1) on the downstream side.
7), and the synthetic resin foam sheet (S) transported from the step roller (17).
A third feed roller (19) that intermittently feeds the material in accordance with the downstream operation, and when the synthetic resin foam sheet (S) conveyed from the third feed roller (19) is fed a predetermined length. , Cut the synthetic resin foam sheet (S) in the folded and unfolded portions from both upper and lower sides of the synthetic resin foam sheet (S) in a direction perpendicular to the conveying direction, and cut the folded portions into 7-shaped shapes. and a seal cutter (20) which is welded and has a Y-shape in plan view, and which is attached to the seal cutter (20) and is used to hold the fused portion of the synthetic resin foam sheet (S') when the seal cutter (20) is operated. It is installed between the ear pressing part (21) of the pair of seal cutters (20) and the ear pressing part (21), and is inserted into the 7-shaped folding part, and is inserted into the synthetic resin foam sheet (S). A heat-resistant Teflon seal receiving plate (22) rotates as it is transported, and a transport conveyor (2) transports a synthetic resin foam sheet (S) with predetermined portions cut and welded.
3>, and this conveyor (23) is connected to the downstream product receiver (
24) is provided with an operating roller (25) that descends at the timing of conveyance to press the synthetic resin foam sheet (S) on the conveyor (23) against the conveyor (23).

The seal cutter (20), as shown in FIG.
A part of the cutter (20a) and a part of the cutter (20a) are provided in the center.
a) The seal part (2
0b), and as shown in FIG. The folded portion of the synthetic resin foam sheet (S) is cut and welded on both sides in two steps. 2Q')
Now, the folded side is diagonally cut so that the intersection point between the linearly welded end surface (indicated by C in Figure 5) and the deep part of the folded part (b in Figure 5) is the end (d). It is configured so that it can be cut and welded in each direction. Further, the seal cutter (20) is configured to be slidable in a direction perpendicular to the conveying direction, and can be positioned according to the depth of the folded portion.

In addition, as the synthetic resin foam sheet (S), in addition to a single foam sheet, a foam sheet laminated with a film can be used. For example, polyethylene, polypropylene, EVA (ethylene vinyl acetate copolymer)
or a foam sheet formed by laminating films made of polyethylene, polypropylene, etc. are used.

Next, the operation of the above manufacturing apparatus and the manufacturing method of the present invention will be described.

The thermoplastic synthetic resin foam sheet (S), which is the original fabric, is
The sheet is pulled out by the first feed roller (13) from two fabric supply rolls (12) provided upstream of the feed roller (13). The first feed roller (13
), the two synthetic resin foam sheets (S) are superimposed and sent to the downstream side sealer (14).
4) Welds one end (b) of the overlapping synthetic resin foam sheets (S). Next, from the outside of the welded end (b), a disc-shaped folding member (15 ), push the end (b) inward. Then, the synthetic resin foam sheet (
S) is formed in a 7-shaped folded part (a), and while maintaining this state, the second feed roller (1B) continues to convey the paper and supplies it to the step roller (17). Step roller (1
7) is composed of five rollers (17a) to (17e) arranged vertically and alternately in different steps, and among them, a roller (17b) and a roller (
17d) are spring-biased in the vertical direction, and the synthetic resin foam sheet (S) is attached to these rollers (
The hooks are passed and conveyed in a zigzag manner to 17a) to (17e). The synthetic resin foam sheet (S) is conveyed continuously up to the second feed roller (18), but is intermittently fed from the third feed roller (19). The rollers (17b) and (17d) provided on the lower side of the rollers (17b) and (17d) are configured to move up and down to take up slack in the synthetic resin foam sheet (S) being conveyed. Then, the third feed roller (1
In step 9), the square bottom bag is intermittently fed by a predetermined length, which is the sum of the horizontal width and 1/2 of the vertical width, and when the conveyance stops, the seal cutter (20) is used to cut the square bottom bag at a predetermined location.・Perform welding. After that, the operating roller (25) above the conveyor (23) is lowered to remove the cut and welded synthetic resin foam sheet (S), that is, the square bottom bag (K).
) on the conveyor (23), and
The product is transported to the product receiver (24). The square bottom bags (K) carried to the product receiver (24) are stacked in predetermined numbers and then packed and shipped. Through the above steps, the overlapping, folding, welding and cutting of the two synthetic resin foam sheets (S) are completed, and the folded square bottom bag (K) is completed.
) is manufactured.

As shown in Fig. 8, the square bottom bag (K) manufactured in this way is expanded inward from the upper open side to create a space. 1) (
2) (2) is formed, and the folded part (e) is extended to form a square bottom (3) as a square bottom bag (K), and at both ends of the square bottom (3), Seal cutter (2
A triangular side part (2') formed by the one-shaped part (20') of 0) is provided seamlessly and continuously with respect to the square base (3), and the triangular side part (2' ) is a part of the side part (2). In addition, the side part (2)
The second seal part (5) appearing in the vertical center of (2) is formed by the straight part (20'') of the seal cutter (20), and the mountain-shaped first seal part (4) is formed by the V-shaped part. (20')
The third seal part (6) appearing from the triangular side part (2') to the central part of the square base (3) is formed by a side sealer (14).

Such a square bottom bag (K) is made of synthetic resin foam sheet (S)
Since the container is formed of , it can absorb shock, so it can suitably store items that may be damaged or damaged, such as agricultural products such as apples and onions.

In the manufacturing method described above, two synthetic resin foam sheets (S) supplied as original sheets are used, one end of which is sealed and folded to form one unit of bag with a predetermined size. Cut to the desired width, weld the side that will form the square bottom into a convex shape,
The cutting process can be performed on a continuous work line, making assembly work possible, contributing to improved production efficiency, and eliminating the need for incidental equipment such as devices for transferring semi-finished products. It is possible to eliminate the risk of increasing costs.

In addition, in the above-mentioned embodiment, the straight part (20~) of the seal cutter (20) that cuts into a predetermined size, and the V-shaped part that forms the first seal part (4) and the second seal part (5). (
20''), but it is easy to manufacture a square bottom bag using separate parts.

In addition, in the above example, the raw material was formed by overlapping two synthetic resin foam sheets (S) and sealing one end, but the synthetic resin foam material as the raw material was formed into a cylindrical shape. If it is a long piece that has been formed, it can be overlapped in a flat shape, and it can be cut in the longitudinal direction or one piece.
It is possible to use a sheet formed by folding two synthetic resin foam sheets in half along the longitudinal direction and overlapping them. By using such a synthetic resin foam sheet, the process of side sealing can be omitted, so side sealers are no longer necessary, and square bottom bags (K)
As shown in Fig. 1, only the first seal part (4) and the second seal part (5) are formed as seal parts, and the triangular side part (2') and the square bottom ( In 3), since no seal portion is formed at all, a square bottom bag (K) with strong peel strength can be formed, which is more effective.

Furthermore, by configuring the folding member (5) and the support member (6) for folding the side end portion of the synthetic resin foam material to be slidable in the folding direction, the folding depth can be adjusted.
In other words, the vertical width of the square bottom bag can be changed, and the shape of the square bottom bag can be easily changed.

EXPERIMENTAL EXAMPLE Next, the results of an experiment comparing the sealing strength between the square-bottomed bag according to the present invention and the conventional square-bottomed bag will be shown.

As a sample, a foamed polyethylene sheet (trade name Nilightron #52) was used, and the square bottom part was formed into the shape described above.
The dimensions are 0 mm x 250 mm and the depth is 150 mm. In the strength experiment, with the bottom of the square bottom bag floating, the four corners of the mouth were supported, and a drop test of the contents was performed on the square bottom to see if the square bottom would break. This is an experiment. Onions were used as containers, and their size was 84 to 87φ in equatorial diameter and 8 in height.
3mm.

The height at the equator is 44 mm5 and the weight is 0.31 kg.

Damage to such onions was examined by changing the height from the base of the cube. The number of samples at the same height was 5 each.

Table (n-5) In the above table, "○" indicates a case where the bag was not damaged, and "x" indicates a case where the bag was damaged.

Note that the damage caused when the falling distance was 1500 mm was not damage to the seal portion, but damage to the sheet portion other than the seal portion.

In the above experiment, onions were dropped one by one into a square-bottomed bag.
When placing multiple onions from a height of , E-mgh (E: potential energy, m-mass, g-
(acceleration, h-height), the square-bottomed bag according to the present invention does not break even if four onions are put in it at once, whereas the conventional square-bottomed bag can hold three onions.
It can be seen that the only allowable value is 2 onions because if you add 1 onion, it will be damaged.

<Effects of the Invention> As described above, according to the square-bottomed bag of the present invention, a mountain-shaped first seal portion is formed on the opposing sides, and the first seal portion is formed linearly upward from the apex of the first seal portion. The bottom part is formed continuously with the triangular side part below the first seal without forming a seam, so that the strength of the square bottom bag is improved. To provide a square bottom bag that is difficult to break by improving the strength at the boundary between the corner bottom and the side, which has been one of the weak points, since there is no joint to join the two. Can be done.

Further, according to the manufacturing method of the present invention, a long raw material is formed into two overlapping sheets with one end joined, and while running in the longitudinal direction, the After folding the ends into a V-shape, cut both ends of the folded side diagonally so that the ends are in the direction perpendicular to the longitudinal direction and the intersection point between this perpendicular direction and the back of the folded part. Since it is welded to form a square bottom bag, each process of manufacturing the bag can be performed on a continuous work line.
As assembly-line work becomes possible, it contributes to improving production efficiency, and since there is no need for incidental equipment for receiving and receiving semi-finished products, it eliminates the risk of increasing equipment costs. Therefore, by implementing this manufacturing method, it is possible to reduce the time, cost, etc. required for manufacturing square bottom bags.
It is possible to provide an inexpensive square bottom bag.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a square bottom bag as an embodiment of the present invention, Figure 2 is a perspective view of the square bottom bag seen from the square bottom side, and Figure 3 is an apparatus implementing the manufacturing method of the present invention. 4 is a schematic plan view of the above device, 5 is a perspective view of a square bottom bag manufactured by the above device, 6 is a sectional view of the seal cutter, and 7 is the seal cutter. FIG. 8 is a perspective view of a square bottom bag manufactured by the above-mentioned manufacturing apparatus, and FIG. 9 is a perspective view of a conventional square bottom bag. (1) (2)...Side part, (2')...Triangular side part, (3)...Square base, (4)...First
Seal part, (5)...Second seal part, (e)...Folding part, (S)...Synthetic resin foam sheet, (K)...
Square bottom bag. Figure 5 Figure 7:)5

Claims (1)

[Claims] 1. On the opposite sides, attach both corners of the bottom side to 2 a mountain-shaped first seal portion having two lower ends; The top of the first seal part at the side part The second series is formed linearly upward from the point. and a bottom portion of the first shell. joint against the triangular side at the lower position of the wall. Continuously formed without seams forming A square bottom bag characterized by: 2.Made of thermoplastic synthetic resin foam material Long raw materials are connected at one side end. Two sheets stacked on top of each other while running in the longitudinal direction. The end portion is 1/2 of the vertical width of the square base. After folding into a V-shape at the depth, in the longitudinal direction Cut at specified intervals in the direction perpendicular to In addition to cutting and welding, welded The intersection point between the end face and the back of the folded part is Tilt both ends of the folded side so that they are the ends. Cut and weld in each direction, A square bottom bag characterized by forming a square bottom Production method.