JP4320160B2 - Plastic bag bottom material folding device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a bag making machine that manufactures a plastic bag using a body material and a bottom material, and more particularly to a bottom material folding device.
[0002]
[Prior art and its problems]
A plastic bag having a body portion, a side gusset portion, and a bottom gusset portion is known. So far, bag making machines for producing the plastic bags have been developed and proposed. For example, what is described in Japanese Patent Application Laid-Open No. 2001-158056 (Patent Document 1).
As shown in the publication, the side gusset portion is formed along both side edges of the trunk portion, folded between both layers of the trunk portion, and folded in two. The bottom gusset portion is formed along the bottom edge of the trunk portion, is folded between both layers of the trunk portion, and is folded in two. Further, both ends of the bottom gusset portion are folded back at an angle of 45 ° with respect to the double fold line of the bottom gusset portion, folded between both layers of the bottom gusset portion, and folded in half. Thus, an auxiliary gusset portion is formed, and one layer of the bottom gusset portion and the auxiliary gusset portion is inserted between one layer of the trunk portion and one layer of the side gusset portion, and the other layer is the other layer of the trunk portion and the other side gusset portion. Inserted between layers. Therefore, the plastic bag can be expanded by the side gusset portion to increase its capacity. A flat bottom surface can be formed by the bottom gusset portion and the auxiliary gusset portion, and the plastic bag can be stably upright.
[0004]
And in the manufacturing process of this plastic bag, with the bag making machine of the above publication, the body material is intermittently fed by a certain length. The body has a body part and a side gusset part. Furthermore, for every intermittent feed of the body, both the upper layer of the body part and the side gusset part are cut, thereby forming a carved part of the carcass, and then in the carved part of the carcass, the bottom material is the carcass part. It is pushed between both layers. Further, when being pushed between the two layers of the body portion, the bottom material is pushed in by a spatula, guided by the bottom material guide member, the bottom material is folded in two along its center line, and both ends thereof are both of the bottom material. Folded between layers.
[0005]
However, in the case of the bag making machine disclosed in the publication, any bottom material cannot be accurately folded and folded. Due to its structure, the size of the bottom material is limited. When the bottom material is large, it is difficult to fold and fold it in half with the spatula and the bottom material guide member.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-158056
OBJECT OF THE INVENTION
Accordingly, the present invention newly provides a bottom material folding device having a special configuration, and when the bottom material of the plastic bag is folded in two along its center line and both ends are folded between both layers of the bottom material, Even if it is a material, it is made so that it can be folded in exactly and folded.
[0008]
[Structure of the invention]
According to the present invention, there is provided a plastic bag bottom material folding device in which the bottom material of the plastic bag is folded in two along its center line, and both ends thereof are folded between both layers of the bottom material,
First and second arms capable of swinging around a support shaft extending along an extension of the center line of the bottom material;
First and second holders supported by the first and second arms, facing each other at a distance, and holding both side edges of the bottom material;
After holding both side edges, the first and second arms are swung in opposite directions around the support shaft, and the first and second holders are rotated together with the first and second arms. A drive mechanism that approaches each other, turns symmetrically, and folds the bottom material in half along its center line;
When the bottom material is folded in half, a plastic bag bottom material folding device is provided which includes a pair of folding members that engage with both ends of the bottom material and fold the both ends between both layers of the bottom material. .
[0010]
In a preferred embodiment, the drive mechanism is connected to the support shaft, and the support shaft is moved by the drive mechanism. The moving direction is a direction perpendicular to the support shaft and the bottom material. Further, the first and second arms are guided by the arm guide member, and the first and second arms swing in the opposite directions as the support shaft moves.
[0011]
Before the both side edges of the bottom material are held by the first and second holders, it is preferable that the bottom material is heated and pressurized with a heater to form a fold in the bottom material.
[0012]
Before the both side edges of the bottom material are held by the first and second holders, the bottom material may be pressed by a press to form a fold in the bottom material.
[0013]
[Explanation of Examples]
Examples of the present invention will be described below.
[0014]
FIG. 1 shows an apparatus according to the present invention. This device is a folding device for the bottom material 1 of a plastic bag, and the bottom material 1 is folded in two along its center line 2 in the same manner as described in Japanese Patent Application Laid-Open No. 2001-158056. Therefore, the fold line 2 is formed by the center line of the bottom material 1. Further, both ends are folded back at an angle of 45 ° with respect to the double fold line 2, folded between both layers of the bottom material 1, and folded in two as in the same publication. Therefore, the fold line 3 is formed at an angle of 45 ° with respect to the fold line 2, and the fold line 4 is formed on the extension line of the fold line 2.
[0015]
In this apparatus, the first and second holders 5a and 5b face each other with a space therebetween, and the side edges 6a and 6b of the bottom material 1 are held by the first and second holders 5a and 5b. In this embodiment, a plurality of air chucks are used for the first holder 5a, and the air chucks 5a are arranged at intervals from each other and attached to the bar 7a. Further, a pair of air cylinders 8a are attached to the base 9a and connected to the bar 7a. The same applies to the second holder 5b. A plurality of air chucks are used for the second holder 5b, and the air chucks 5b are spaced from each other and attached to the bar 7b. Further, a pair of air cylinders 8b are attached to the base 9b and connected to the bar 7b.
[0016]
Furthermore, as shown in FIG. 2, the bottom material 1 is adsorbed by the adsorbing belt 10, sent to the position of FIG. 1, and disposed between the first and second holders 5a and 5b. The bottom material 1 may be sucked not by the suction belt 10 but by the suction pad, and sent to the position shown in FIG. 1 and disposed between the first and second holders 5a and 5b. Therefore, thereafter, as shown in FIGS. 3 and 5, the bars 7 a and 7 b are moved by the air cylinders 8 a and 8 b, and the first and second holders 5 a and 5 b are moved toward both side edges 6 a and 6 b of the bottom material 1. When the air chucks 5a and 5b are closed by air, the side edges 6a and 6b of the bottom material 1 are gripped by the air chucks 5a and 5b. Therefore, both side edges 6a and 6b of the bottom material 1 are held by the first and second holders 5a and 5b. Thereafter, the bottom material 1 is released from the suction belt 10 or the suction pad.
[0017]
Further, in this embodiment, the bottom material 1 is folded before the both side edges 6a, 6b of the bottom material 1 are held by the first and second holders 5a, 5b. For example, as in the bag making machine disclosed in Japanese Patent Application Laid-Open No. 2001-158056, the bottom material 1 is heated and pressurized by a heater, thereby forming a fold. Then, after the folding is formed, it is sent to the position shown in FIG. 1, and both side edges 6a, 6b of the bottom material 1 are held by the first and second holders 5a, 5b. The fold is formed along the fold lines 2 and 4 and the fold line 3 of the bottom material 1. The bottom material 1 may be pressurized by pressing to form a fold.
[0018]
Furthermore, in this apparatus, after holding the side edges 6a and 6b, the first and second holders 5a and 5b are operated by the drive mechanism, and the first and second holders 5a and 5b approach each other, and at the same time, It turns around both side edges 6a and 6b and turns symmetrically. In this embodiment, the first and second arms 11a and 11b are combined with the bases 9a and 9b, connected to one end thereof, and integrated, and the bases 9a and 9b are cantilevered. Accordingly, the first and second holders 5a and 5b are supported by the first and second arms 11a and 11b. Further, the first and second arms 11a and 11b are fixed to the first and second bosses 12a and 12b. The bosses 12a and 12b are fitted to and supported by the support shaft 13, and can rotate around the support shaft 13. It is. Therefore, the first and second arms 11a and 11b can swing around the support shaft 13 and swing integrally with the bosses 12a and 12b. The support shaft 13 extends along an extension line of the center line 2 of the bottom material 1. Then, the drive mechanism acts on the first and second arms 11a and 11b, and the first and second arms 11a and 11b swing in the opposite directions around the support shaft 13. As a result, the first and second holders 5a and 5b approach and turn.
[0019]
Furthermore, in this embodiment, as shown in FIG. 4, the drive mechanism is composed of an air cylinder 14 and is connected to the support shaft 13. Further, a spring 15 is provided around the support shaft 13, and both ends thereof are engaged with the first and second bosses 12 a and 12 b, and around the support shaft 13, the spring 15 is connected to the bosses 12 a and 12 b and the arm 11 a. , 11b, the first and second arms 11a, 11b are elastically biased in opposite directions to engage the arm guide members 16a, 16b. The arm guide members 16 a and 16 b are composed of first and second stoppers and are arranged on both sides of the support shaft 13. Therefore, the arms 11a and 11b and the support shaft 13 are positioned and supported by the stoppers 16a and 16b and the air cylinder 14.
[0020]
Then, after holding both side edges 6a and 6b of the bottom material 1, the support shaft 13 is pushed by the air cylinder 14 and moved. The moving direction is a direction perpendicular to the support shaft 13 and the bottom material 1. Accordingly, the first and second bosses 12a and 12b are pulled by the support shaft 13, and the first and second arms 11a and 11b are drawn between the first and second stoppers 16a and 16b, as shown in FIGS. As described above, the first and second arms 11a and 11b are guided by the first and second stoppers 16a and 16b, and the first and second arms 11a and 11b swing in the opposite directions as the support shaft 13 moves. . As a result, the first and second arms 11a and 11b are folded, and the angle α gradually decreases.
[0021]
Therefore, the first and second holders 5a and 5b swing integrally with the first and second arms 11a and 11b, and as shown in FIGS. 7 and 8, the first and second arms 11a and 11b swing. With the movement, the first and second holders 5a and 5b approach each other, and at the same time, rotate around both side edges 6a and 6b of the bottom material 1 to be symmetrically changed. In this state, the first and second arms 11a and 11b are folded. Further, as described above, the fold is formed along the double fold line 2 of the bottom material 1. Therefore, the bottom material 1 is folded in half by the first and second holders 5a and 5b, and the fold line 2 is formed. When the bottom material 1 is folded in half, its shape corresponds to that of the first and second arms 11a, 11b. The angle β also corresponds to the angle α of the first and second arms 11a and 11b, gradually decreases, the fold line 2 is displaced in the moving direction of the support shaft 13, and the position thereof is kept on the extension line of the support shaft 13. It is.
[0022]
Further, as described above, the folding is formed along the folding line 3 and the double folding line 4 of the bottom material 1. In this embodiment, as shown in FIG. 10, when the bottom member 1 is folded in half, a pair of folding members 17 engages both ends of the bottom member 1 in accordance with the displacement. Therefore, both ends are folded back by the folding member 17 and folded in two to form the folding line 3 and the double folding line 4, and the folding member 17 is inserted between both layers at both ends. As a result, the bottom gusset portion 18 and the auxiliary gusset portion 19 are formed.
[0023]
In the case of this device, both side edges 6a and 6b of the bottom material 1 may be held by the first and second holders 5a and 5b, and even the large bottom material 1 can be easily folded in two and folded. it can. In addition, the two side edges 6a and 6b of the bottom material 1 are held and restrained by the first and second holders 5a and 5b while being folded in two, and the first and second holders 5a and 5b approach in this state. And turn around. Therefore, the bottom material 1 can be accurately folded and folded.
[0024]
Furthermore, in this embodiment, when the bottom material 1 is folded in two, it is sandwiched between a pair of rollers 20, and the bottom material 1 is pulled by the rollers 20. At the same time, the air chucks 5a and 5b are opened by air, and the bottom material 1 is released from the first and second holders 5a and 5b. Accordingly, the bottom material 1 is separated from the first and second holders 5 a and 5 b and drawn between the rollers 20. Thereafter, the bottom material 1 is compressed between the rollers 20, completely folded in two, and completely folded. Further, at the center of the folded bottom material 1, it is sandwiched between a pair of narrow belts 21, and when the bottom material 1 passes the roller 20 as shown in FIG. The material 1 is held and moved. The narrow belt 21 is bent downward, and the bottom material 1 is held in a downward state, stops at that position, and waits.
[0025]
This apparatus is incorporated in a bag making machine, and the bag making machine is of the same type as the bag making machine disclosed in Japanese Patent Application Laid-Open No. 2001-158056. Therefore, as described in the publication, the barrel 22 is intermittently fed by a certain length. The body 22 has a body part 23 and a side gusset part 24. Each time the body 22 is intermittently fed, both the upper layer of the body portion 23 and the side gusset portion 24 are cut, thereby forming a slit portion 25 of the body material 23. Further, thereafter, every time the body 22 is intermittently fed, the slit 25 reaches the position of the guide roller 26, the body 22 is bent by the guide roller 26, and the upper layer of the body 23 is adsorbed by the suction pad 27. The cut portion 25 is opened by the pad 27. And in the cut-off part 25 of the trunk | drum 22, the bottom material 1 is pushed into both the layers of the trunk | drum 23. FIG.
[0026]
Further, in this embodiment, after the bottom material 1 is folded, the bottom material 1 is held by the narrow belt 21 and the bottom material 1 waits in a downward state as described above. , The cut-out portion 25 is arranged upward and opened. Thereafter, for example, a pair of guide plates 28 advance toward the body 22 and the bottom material 1 on both sides of the body 22 and the bottom material 1 and are inserted between both layers of the side gusset portion 24, so that the auxiliary gusset portion 19. Inserted between both layers. Next, on both sides of each guide plate 28, two pairs of pushing fingers 29 are lowered along the guide plate 28 and inserted into the bottom material 1. The position is between the bottom gusset portion 18 and the auxiliary gusset portion 19. Then, the bottom material 1 is pushed down by the pushing finger 29, and the bottom material 1 descends along the guide plate 28 and is pulled out from the narrow belt 21. Furthermore, when the bottom material 1 is pushed down, the narrow belt 21 may be opened by the drive mechanism, and the bottom material 1 may be released from the narrow belt 21.
[0027]
Therefore, the bottom material 1 is pushed between the two layers of the body 23 in the opening 25 of the body 22. As for the auxiliary gusset portion 19, one layer of the bottom gusset portion 18 and the auxiliary gusset portion 19 is inserted between one layer of the body portion 23 and one layer of the side gusset portion 24, and the other layer is side by side with the other layers of the body portion 23. It is inserted between other layers of the gusset portion 24. Thereafter, the pushing finger 29 is raised to the original position, pulled out from the bottom material 1, and the guide plate 28 is moved back to the original position. Thereafter, similar to the bag making machine disclosed in Japanese Patent Laid-Open No. 2001-158056, the body 22 and the bottom material 1 are intermittently fed by the lower layer of the body portion 23, and the body 22 and the bottom material 1 are heat-sealed by a heat sealing device. It is cut by the cutter. Thereby, a plastic bag is manufactured.
[0028]
On the other hand, as described above, the bottom material 1 is released from the first and second holders 5a and 5b and drawn between the rollers 20, but the holders 5a and 5b are The bars 7a and 7b and the holders 5a and 5b are moved and moved backward by the air cylinders 8a and 8b. Further, the support shaft 13 is moved by the air cylinder 14, and the support shaft 13 returns to the position shown in FIG. Therefore, the arms 11a and 11b and the holders 5a and 5b are swung by the spring 15, the arms 11a and 11b are also returned to the positions shown in FIG. 4, and the holders 5a and 5b are returned to the positions shown in FIGS. Therefore, after that, the bottom material 1 can be sent to the position shown in FIGS. 1 and 2, and the side edges 6a and 6b of the bottom material 1 can be held by the first and second holders 5a and 5b. Furthermore, after that, the first and second arms 11a and 11b can be swung again, and the bottom material 1 can be folded and folded again.
[0029]
In the case of this apparatus, the holders 5a and 5b can be moved backward by the air cylinders 8a and 8b and returned to the positions shown in FIGS. 1 and 2, and the bottom material 1 is located at the positions shown in FIGS. However, when returning to the position of FIG. 1 and FIG. 2, the holders 5a and 5b do not interfere with the bottom material 1, and there is no problem. Therefore, when the previous bottom material 1 is folded in two and folded, the next bottom material 1 can be sent to the position shown in FIGS. 1 and 2 in parallel therewith, which is efficient.
[0030]
【The invention's effect】
As described above, according to the present invention, even a large bottom material 1 can be accurately folded and folded, and the intended purpose can be achieved.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is a side view showing a relationship between a holder and a bottom material of the apparatus of FIG.
3 is a front view showing a next step of the apparatus in FIG. 1. FIG.
4 is a side view showing a relationship between an arm and a stopper of the apparatus shown in FIG. 3;
5 is a side view showing the relationship between the holder and the bottom material of the apparatus of FIG. 3. FIG.
6 is a side view showing the next step of the apparatus in FIG. 4; FIG.
7 is a side view showing the relationship between the holder and the bottom material of the apparatus of FIG. 6. FIG.
FIG. 8 is a side view showing the next step of the apparatus of FIG. 6;
9 is a side view showing the relationship between the holder and the bottom material of the apparatus of FIG.
10 is a plan view showing the relationship between the folding member and the bottom member of the apparatus of FIG. 8. FIG.
11 is a side view showing a bottom material pushing mechanism of the apparatus of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bottom material 5a, 5b Holder 6a, 6b Both-sides edge 11a, 11b 1st and 2nd arm 13 Support shaft 14 Air cylinder 16a, 16b Stopper

Claims (4)

A plastic bag bottom material folding device that folds the bottom material of a plastic bag in two along its center line and folds both ends of the bottom material between both layers of the bottom material,
First and second arms capable of swinging around a support shaft extending along an extension of the center line of the bottom material;
First and second holders supported by the first and second arms, facing each other at a distance, and holding both side edges of the bottom material;
After holding both side edges, the first and second arms are swung in opposite directions around the support shaft, and the first and second holders are rotated together with the first and second arms. A drive mechanism that approaches each other, turns symmetrically, and folds the bottom material in half along its center line;
When the bottom material is folded in half, a plastic bag bottom material folding device comprising a pair of folding members that engage with both ends of the bottom material and fold both ends between both layers of the bottom material. The drive mechanism is coupled to the support shaft, and the support shaft is moved by the drive mechanism, the moving direction is a direction perpendicular to the support shaft and the bottom material, and further, the first guide by the arm guide member. 2. The bottom material folding device according to claim 1 , wherein the first and second arms swing in the opposite directions as the support shaft moves and the second arm is guided. Claims, characterized in that the said the first and second holder before both side edges of the base material is maintained, heat and pressure said bottom member by a heater, and to form a habit folding said bottom member The bottom material folding device according to 1 or 2 . 2. The bottom material is pressed by a press before both side edges of the bottom material are held by the first and second holders, and a fold is formed in the bottom material. The bottom material folding apparatus according to 2.

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