JPH0254217B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a square bottom bag made of synthetic resin,
More specifically, the present invention relates to a method for continuously manufacturing a square bottom bag made of synthetic resin in which a bottom plate is joined to the square bottom portion.

Bags made of synthetic resin (plastic film) are
They are superior to paper bags in various aspects such as water resistance, mechanical strength, and surface gloss, and are therefore used for a wide range of purposes. However, since synthetic resin bags generally have a weak film, they do not have sufficient independence when storing articles or stability when placed on the bag after storing articles. As an improvement on this point, it is already known that the entire bag is made of relatively thick paper with a synthetic resin layer laminated on the surface, but such bags are expensive. I didn't get it. In addition, bags with a reinforcing bottom plate made of cardboard or resin sheet attached to the bottom of the bag are already known, but in the case of such bags, the bottom plate is attached manually with adhesive. This pasting process required a great deal of labor and time. Moreover, resin films such as polyethylene have poor adhesive properties, and there are restrictions on the types of adhesives that can be used, which also leads to an increase in manufacturing costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently manufacturing a square bottom bag made of synthetic resin in which a bottom plate is joined to the square bottom portion.

The present invention includes a cutting step of cutting a gusseted flat cylindrical film into a predetermined length, a bottom welded portion forming step of welding the flat cylindrical film in the width direction to form a bottom welded portion, and a bottom welded portion forming step of forming a bottom welded portion by welding the flat cylindrical film in the width direction. A core for holding the bottom plate is inserted on the tip side of the flat cylindrical film in which the welded portion is formed, and the tip of the core is rotated to rotate the bottom plate in the vicinity of the bottom welded portion. a corner bottom forming step in which a corner bottom is formed; a bottom plate bonding step in which the bottom plate is bonded to the corner bottom by pressing a heater from the outside of the corner bottom to which the bottom plate is abutted; and a bottom plate joining step in which the bottom plate is bonded to the corner bottom after the bottom plate bonding step. A core extraction step of releasing the bottom plate from the tip side of the core and then extracting the core from within the cylindrical film, and
A plurality of cores are arranged radially in a rotating mechanism, and a cylindrical film is inserted into and removed from the cores, and as the cores are rotated, the steps of forming the square bottom part, the step of joining the bottom plate, and the process of joining the cores are performed in order. The objective is to be achieved by carrying out a child extraction process.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 schematically shows the overall configuration of a manufacturing apparatus to which an embodiment of the method for manufacturing square bottom bags made of synthetic resin according to the present invention is applied. The flat cylindrical film 2 is wound up in many layers. The flat cylindrical film 2 is made of a synthetic resin, preferably a soft synthetic resin such as polyethylene or polypropylene. The thickness of the flat cylindrical film 2 is variously selected depending on the purpose and size of the square bottom bag to be manufactured, but is usually 10 μm or more.
It is about 200 μm.

A flat cylindrical film 2 fed from an original film 1 is suspended between a pair of presser plates 5 via transfer rollers 3 and 4 consisting of a pair of roller bodies. The holding plates 5 are disposed opposite to each other so as to sandwich the film 2 in the width direction from both sides of the flat cylindrical film 2, and provide biasing means for a reciprocating member 6 that advances and retreats toward the film 2 from both sides of the film 2. It is attached through. A cutter 7 is provided near the lower side of the presser plate 5 of the advancing/retracting member 6 in the figure, and a heat sealer 8 is provided further below the cutter 7. When the film 2 is held between both sides, the flat cylindrical film 2 is held and fixed from both sides by the press plate 5, cut by the cutter 7 in the width direction, and cut by the heat sealer 8 in the width direction. Welded. That is, a cutting process is performed in which the flat cylindrical film 2 is cut into a predetermined length by the cutter 7,
Further, a bottom welded portion forming step is performed in which the flat cylindrical film 2 is welded in the width direction using the heat sealer 8 to form the bottom welded portion 11 .

A bag member 12 made of a flat cylindrical film 2 cut in the width direction by a cutter 7 and having a bottom welded portion 11 is suspended by its own weight or by a transport means (not shown).
A core 21 is inserted inside. A plurality of cores 21 are arranged radially around the rotation mechanism 22 along the circumferential direction, and the plurality of cores 21 are configured to be sequentially rotated in the counterclockwise direction in FIG. 1 around the rotation mechanism 22. There is.

As shown in FIG. 2, the tip end side of the core 21 is provided with a rotary disk 23 formed into a substantially thick-walled hollow rectangular disk shape.
The rotary disk 23 is rotatably supported via a support shaft 25 at the tips of two support rods 24 arranged parallel to each other. The rotary disk 23 includes a suction portion 26 on which the support shaft 25 is provided at both ends;
and a blow-off section 27 disposed on the tip edge side of the suction section 26, and the suction section 26 and the blow-off section 27 each have an independent hollow portion that is not communicated with each other.

Further, as shown in FIG. 3, one side of the suction portion 26 and the blow-off portion 27 form the same plane, and a plurality of suction holes 28 are bored in the surface of the suction portion 26. There is. In addition, the adsorption section 26
The other end of a flexible tube 29 is connected to one end of the flexible tube 29 to which a suction mechanism (not shown) is connected.
1 is adsorbed and held in a removable manner. Here, examples of the material of the bottom plate 31 include cardboard, thermoplastic resin sheet, etc.
If cardboard is used, it is preferable to use one whose surface is coated with a resin such as polyethylene in order to ensure easy and reliable bonding with the bag member 12. The thickness of the bottom plate 31 can be selected depending on the application, but is usually about 0.1 mm to 2 mm.

A recess 33 is formed approximately at the center of one end edge of the suction portion 26, and a rotation shaft 34 is fixed within the recess 33. A timing pulley having a substantially gear-shaped cross section is attached to the rotation shaft 34. 35 is fitted and fixed, and an endless timing belt 36 is wound around this timing pulley 35. The rotation shaft 34 is disposed on the same straight line as the support shaft 25, while a driving source (not shown) such as a stepping motor is connected to the lower end side of the timing belt 36 in FIG. By driving the timing belt 36 in forward and reverse directions by the drive source, the rotary disk 23 is configured to be appropriately rotated on the tip side of the support rod 24.

Further, a blowout hole 37 is provided at the upper end edge of the blowout portion 27 in FIG.
7 is connected to the other end of a flexible tube 38 whose one end is connected to an air supply mechanism (not shown).
When air is supplied into the blow-off portion 27 through the blow-off hole 37, the air is blown out from the blow-off hole 37.

When inserting the core 21 into the bag member 12, the bottom plate supply mechanism 81 ( The upper half of the bottom plate 31 (see FIG. 1) supplied from the bottom plate 31 is adsorbed. At this time, the bag member 12 is opened and inserted smoothly by blowing out air from the blow-off hole 37. Ru. Note that the bag member 12 is connected to the blowout hole 37.
When opening the bag member 12 by blowing air from the bag member 12, a pressing member may be placed near the outside of the opening of the bag member 12, or a suction means or the like may be used to assist the opening.

After inserting the core 21 so as to reach the bottom welding part 11 of the bag member 12, the timing belt 36 is rotated to rotate the bottom plate 31 in the vicinity of the bottom welding part 11 of the bag member 12, and finally , the rotating plate 23 is rotated to a vertical position with respect to the support rod 24, in other words, the bottom plate 31 is moved to the bottom welded part 1.
The corner bottom 4 is rotated to a vertical position in the vicinity of 1.
1 (see Figure 3). Here, a corner bottom forming step will be performed. Further, the bottom plate 31 is brought into contact with the inside of the formed square bottom portion 41.

When rotating the rotating disc 23 at the tip of the core 21, the bag member 12 is rotated by the holding rollers 45 and 46.
In a state where the bottom welded part 11 side is substantially closed,
This is done while blowing an appropriate amount of air into the bag member 12 through the blow-off hole 37. As a result, the bottom welded portion 1 is
Although both ends of the bag member 12 on the first side are gusset-folded, the turning operation of the turning plate 23 and the bottom plate 31 in the vicinity of the bottom welded portion 11 is performed smoothly, and therefore the square bottom portion 41 is formed easily. will also be ensured.

As shown in FIG. 3, the rotation shaft 51 of the clamping roller 46 is rotatably supported by support rods 52 arranged parallel to each other.
1, one end sides of rotating rods 53 arranged parallel to each other are rotatably supported. Rotating rod 5
3, one edge of a rectangular plate-shaped presser plate 54 is rotatably supported. The holding plate 54 is biased counterclockwise in the figure by a coil spring 55, and one end of an operating wire 56 is fixed to a predetermined position on the rotating end side of the holding plate 54. By appropriately pulling the wire 56, the presser plate 54 is rotated on the tip side of the rotating rod 53 according to or against the biasing force of the coil spring 55.

After the bottom plate 31 is rotated by the rotating disk 23 to form the square bottom part 41, the presser plate 54 is placed on the back surface of the bottom plate 31 on the side that is not sucked by the suction part 26. When placing the presser plate 54, the presser plate 54 is held perpendicular to the rotating rod 53, and the rotating rod 53 is rotated by a rotating mechanism (not shown) so that the rotating rod 53 is parallel to the support rod 24. be located at In this state, about half of the back side of the bottom plate 31 is supported by the suction part 26, and the other half is supported by the presser plate 54. In this state, the heater 61 having a planar heating part is attached to the bag. The bottom plate 31 is joined to the square bottom part 41 by pressing the member 12 against the square bottom part 41 from the outside and thermally welding the square bottom part 41 and the bottom plate 31 to each other. At this point, a bottom plate bonding step will be performed. Note that the joining by thermal welding between the square bottom portion 41 and the bottom plate 31 may be performed over the entire surface of the bottom plate 31, or may be welded and joined in a linear shape of a predetermined shape. The heating temperature of the heater 61 is usually 150°C to
The temperature is around 250℃. In this way, 100 square bottom bags
is formed.

After the bottom plate 31 is joined to the square bottom part 41, the bottom plate 31 is attached to the rotating plate 23 while the bottom plate 31 is attached to the rotating plate 23.
is rotated clockwise in FIG.
is rotated in the same direction. As a result, the corner bottom portion 41 to which the bottom plate 31 is joined is folded.
During or after the folding operation of the corner bottom 41, the corner bottom 41 is held between folding rollers 71 consisting of a pair of roller bodies (see FIG. 1).

Also, in a state where the square bottom portion 41 is folded to some extent, the bottom plate 31 is released from the rotary plate 23,
As shown in FIG. 4, the folding roller 71
The square bottom bag 100 is held while pinching the folded square bottom part 41, whereby the square bottom bag 100
is pulled out from the core 21. At this point, a core extraction step is performed to extract the square bottom bag 100 from the core 21. Note that when the square bottom bag 100 is removed from the core 21, the presser plate 54 is rotated clockwise in FIG. There seems to be no danger of this happening. In addition, when extracting, the rotary plate 23
This may be done while blowing out air from the blow-off hole 37.

The square bottom bag 100 extracted from the core 21 is
As shown in the figure, the rotary plate 2 is sequentially stocked on the stock stand 72 and the bottom plate 31 is removed.
3, the bottom plate 31 is again supplied from the bottom plate supply mechanism 81.

According to this embodiment, one core 21
Insertion of the bottom plate 31 into the bag member 12 and the bottom plate 3
1, and the core 21 also serves as a receiving plate when the bottom plate 31 and the square bottom 41 are joined by the welding heater 61. This has the effect that the square bottom bag 100 made of synthetic resin in which the bottom plate 31 is joined to the square bottom portion 41 can be efficiently manufactured.

Moreover, since the square bottom part 41 is pulled out from the core 21 in a folded state by the folding roller 71, the square bottom bags 100 are sequentially manufactured with the square bottom part 41 in a folded state. It is extremely convenient to store the square bottom bag 100.

Furthermore, since the bottom plate 31 is welded to the corner bottom 41, the adhesion of the bottom plate 31 is lower than, for example, when a bottom plate made of cardboard or the like is stuck to the corner bottom using a conventional adhesive. This has the effect of stabilizing quality.

In this implementation, it was assumed that the bottom plate 31 was removably held on the rotary plate 23 by a suction means. Bottom plate 31
may be maintained. However, if a suction mechanism is used, the structure of the rotating disc 23 can be made simpler, and there is no risk of damaging the film surface of the bag member 12.
Moreover, when inserting the bag member 12 into the core 21, air is blown from the blow-off hole 37 of the blow-off part 27, but blowing out of air is not necessarily necessary. However, if air is blown out as described above, the bag member 12 can be opened easily and the core 21 can be easily moved into the bag member 12. In addition, by rotating the rotating disc 23 on the bag bottom side of the bag member 12, the square bottom 11
Although the formation of the bag member 12 is performed while blowing air from the blowing hole 37, it is not necessarily necessary to rotate the rotary plate 23 while blowing air. The square bottom portion 41 can be formed by easily rotating the rotating plate 23, in other words, the bottom plate 31, without causing wrinkles or the like.

Further, although the holding plate 54 is not necessarily required, by providing the holding plate 54, the strength of the receiving part can be ensured when the bottom plate 31 and the square bottom part 41 are joined by the heater 61. Therefore, there is an effect that the bottom plate 31 and the square bottom portion 41 can be easily joined more reliably. Further, in the above embodiment, the square bottom portion 41 was folded by the folding roller 71 and removed from the core 21.
The bag member 12 may be removed from the core 21 without folding the corner bottom portion 41. However, it is extremely convenient to store the square bottom bag 100 if it is pulled out after being folded.

As described above, according to the present invention, after the process of cutting the cylindrical film and the process of forming the bottom welded part,
During one rotation of the core into which the cylindrical film is inserted and removed by the rotation mechanism, the corner bottom forming process, bottom plate bonding process, and core extraction process are performed in order, so the synthetic resin square with the bottom plate bonded to the corner bottom is Bottom bags can be manufactured efficiently through continuous automatic operation.

In addition, while the core is inserted into the cylindrical film, the cylindrical film undergoes a corner bottom forming process, a bottom plate joining process,
Since the cylindrical film and the core are sent to the core extraction process, the cylindrical film and the core are sent to each process while maintaining a predetermined positional relationship, so that the work performed on the corner bottom of the cylindrical film can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a front view showing the overall configuration of a manufacturing device to which an embodiment of the method for manufacturing a synthetic resin square bottom bag according to the present invention is applied, and FIGS. 2 to 4 show operating states of the main parts of the manufacturing device, respectively. FIG. 7...Katsuta, 8...Heat sealer, 11...
Bottom welded part, 12... Bag member, 21... Core, 2
2... Rotation mechanism, 23... Turning plate, 31... Bottom plate, 41... Corner bottom, 45, 46... Holding roller, 54... Holding plate, 61... Heater, 71...
Folding roller, 100...square bottom bag.

Claims (1)

[Scope of Claims] 1. A cutting step of cutting the gusseted flat cylindrical film into a predetermined length, and a bottom welded portion forming step of welding the flat cylindrical film in the width direction to form a bottom welded portion. A core that holds the bottom plate is inserted on the tip side into the flat cylindrical film in which the bottom welded portion is formed, and the tip of the core is rotated to rotate the bottom plate in the vicinity of the bottom welded portion. a square bottom forming step in which a square bottom is formed by pressing the bottom plate, a bottom plate joining step in which the bottom plate is joined to the square bottom by pressing a heater from the outside of the square bottom with the bottom plate in contact with the inner side, and a bottom plate joining step in which the bottom plate is joined to the square bottom after the bottom plate joining step a core extraction step of releasing the bottom plate from the front end side of the core and extracting the core from within the cylindrical film, wherein a plurality of the cores are arranged radially in a rotating mechanism and the cores are cylindrical with respect to the core. A method for manufacturing a synthetic resin square bottom bag, characterized in that the film is inserted and removed, and as the core rotates, the square bottom forming step, the bottom plate joining step, and the core removal step are performed in order.